Secure file sharing method and system

ABSTRACT

Systems and methods are provided for securely sharing data. A processor forms two or more shares of a data set encrypted with a symmetric key, the data set associated with a first user device, and causes the encrypted data set shares to be stored separately from each other in at least one remote storage location. The processor generates first and second encrypted keys by encrypting data indicative of the symmetric key with a first asymmetric key of first and second asymmetric key pairs associated with the first user device and a second user device, respectively, and causes the encrypted key to be stored in the at least one storage location. To restore the data set, a predetermined number of the two or more encrypted data set shares and at least one of the second asymmetric keys of the first and second asymmetric key pairs are needed.

CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation application of U.S. patent application Ser. No.13/413,195, filed Mar. 6, 2012, which claims priority benefit under 35U.S.C. 119(e) from U.S. Provisional Application No. 61/450,110, filedMar. 7, 2011. Each of the aforementioned, earlier-filed applications ishereby incorporated by reference herein in its entirety.

SUMMARY

Described herein are systems and methods for securely sharing data andaccessing securely shared data. In some aspects, a method for securelysharing data is provided, the method steps implemented by a programmedcomputer system. Two or more shares of an encrypted data set are formed.The encrypted data set is representative of a data set associated with afirst user device and is encrypted with a symmetric key. Each encrypteddata set share includes a portion of data from the encrypted data set,and the two or more encrypted data set shares are caused to be storedseparately from each other in at least one storage location. The atleast one storage location may include a cloud computing storagelocation. A first encrypted key is generated by encrypting dataindicative of the symmetric key with a first asymmetric key of a firstasymmetric key pair associated with the first user device. A secondencrypted key is generated by encrypting data indicative of thesymmetric key with a first asymmetric key of a second asymmetric keypair associated with a second user device. In some implementations, themethod includes accessing the first asymmetric key of the secondasymmetric key pair from a registration server prior to generating thesecond encrypted key. The first and second encrypted keys are caused tobe stored in the at least one storage location, which is remote to boththe first and second user devices. To restore the data set, apredetermined number of the two or more encrypted data set shares and atleast one of a second asymmetric key of the first asymmetric key pairand a second asymmetric key of the second asymmetric key pair areneeded.

In some implementations, the data indicative of the symmetric key is thesymmetric key. In some implementations, the data indicative of thesymmetric key is the symmetric key encrypted with a workgroup key. Insome such implementations, the workgroup key is needed to restore thedata set. The second user device may be associated with a workgroup thathas access to the workgroup key.

In some implementations, the method includes forming two or more sharesof the first and second encrypted keys, each encrypted key shareincluding a portion of data from the first and second encrypted keys. Insome such implementations, causing the first and second encrypted keysto be stored in the at least one storage location includes causing thetwo or more encrypted key shares to be stored separately from each otherin the at least one storage location. To restore the first and secondencrypted keys, a predetermined number of the two or more encrypted keyshares is needed.

In some implementations, the method includes generating a plurality ofencrypted keys by, for each of a plurality of first asymmetric keys of acorresponding plurality of asymmetric key pairs associated with acorresponding plurality of user devices, encrypting the data indicativeof the symmetric key with the first asymmetric key. The plurality ofencrypted keys are caused to be stored in the at least one storagelocation (which may include transmitting the plurality of encrypted keysin a header of each of the two or more encrypted data set shares). Torestore the data set, the predetermined number of the two or moreencrypted data set shares and at least one of the second asymmetric keyof the first asymmetric key pair, the second asymmetric key of thesecond asymmetric key pair, and the plurality of second encryption keysof the plurality of asymmetric key pairs are needed.

In some aspects, a method for accessing a securely shared data set isprovided, the method steps implemented by a programmed computer system.A first encrypted key stored in at least one storage location isaccessed. The first encrypted key includes data indicative of asymmetric key encrypted with a first asymmetric key of a firstasymmetric key pair associated with a first user device. In someimplementations, the first asymmetric key of the first asymmetric keypair is provided to a registration server prior to accessing the firstencrypted key. The at least one storage location is remote from thefirst user device and remote from a second user device different fromthe first user device. The at least one storage location also stores asecond encrypted key comprising data indicative of the symmetric keyencrypted with a first asymmetric key of a second asymmetric key pairassociated with the second user device. The data indicative of thesymmetric key is restored by decrypting the first encrypted key using asecond asymmetric key of the first asymmetric key pair. A predeterminednumber of two or more encrypted data set shares stored in the at leastone storage location (encrypted with the symmetric key by the seconduser device) are accessed. The data set is then restored using thepredetermined number of encrypted data set.

In some aspects, a method for securely sharing data is provided, themethod steps implemented by a programmed computer system. Two or moreshares of an encrypted data set are formed, the encrypted data setrepresentative of a data set associated with a first user device andencrypted with a symmetric key. Each encrypted data set share includes aportion of data from the encrypted data set. For each of a plurality ofuser devices including the first user device, an encrypted key isgenerated by encrypting data indicative of the symmetric key with afirst asymmetric key of an asymmetric key pair associated with the userdevice. For each of the two or more encrypted data set shares, theplurality of encrypted keys is distributed in a header of the encrypteddata set share, and the two or more encrypted data set shares andheaders are caused to be stored in at least one storage location. Torestore the data set, a predetermined number of the two or moreencrypted data set shares and a second asymmetric key of at least one ofthe plurality of asymmetric key pairs are needed to restore the dataset.

Systems and computer-readable media configured to execute the methodsdisclosed herein are also provided.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is described in more detail below in connectionwith the attached drawings, which are meant to illustrate and not tolimit the invention, and in which:

FIG. 1 illustrates a block diagram of a cryptographic system, accordingto aspects of an embodiment of the invention;

FIG. 2 illustrates a block diagram of the trust engine of FIG. 1,according to aspects of an embodiment of the invention;

FIG. 3 illustrates a block diagram of the transaction engine of FIG. 2,according to aspects of an embodiment of the invention;

FIG. 4 illustrates a block diagram of the depository of FIG. 2,according to aspects of an embodiment of the invention;

FIG. 5 illustrates a block diagram of the authentication engine of FIG.2, according to aspects of an embodiment of the invention;

FIG. 6 illustrates a block diagram of the cryptographic engine of FIG.2, according to aspects of an embodiment of the invention;

FIG. 7 illustrates a block diagram of a depository system, according toaspects of another embodiment of the invention;

FIG. 8 illustrates a flow chart of a data splitting process according toaspects of an embodiment of the invention;

FIG. 9, Panel A illustrates a data flow of an enrollment processaccording to aspects of an embodiment of the invention;

FIG. 9, Panel B illustrates a flow chart of an interoperability processaccording to aspects of an embodiment of the invention;

FIG. 10 illustrates a data flow of an authentication process accordingto aspects of an embodiment of the invention;

FIG. 11 illustrates a data flow of a signing process according toaspects of an embodiment of the invention;

FIG. 12 illustrates a data flow and an encryption/decryption processaccording to aspects and yet another embodiment of the invention;

FIG. 13 illustrates a simplified block diagram of a trust engine systemaccording to aspects of another embodiment of the invention;

FIG. 14 illustrates a simplified block diagram of a trust engine systemaccording to aspects of another embodiment of the invention;

FIG. 15 illustrates a block diagram of the redundancy module of FIG. 14,according to aspects of an embodiment of the invention;

FIG. 16 illustrates a process for evaluating authentications accordingto one aspect of the invention;

FIG. 17 illustrates a process for assigning a value to an authenticationaccording to one aspect as shown in FIG. 16 of the invention;

FIG. 18 illustrates a process for performing trust arbitrage in anaspect of the invention as shown in FIG. 17; and

FIG. 19 illustrates a sample transaction between a user and a vendoraccording to aspects of an embodiment of the invention where an initialweb based contact leads to a sales contract signed by both parties.

FIG. 20 illustrates a sample user system with a cryptographic serviceprovider module which provides security functions to a user system.

FIG. 21 illustrates a process for parsing, splitting and/or separatingdata with encryption and storage of the encryption master key with thedata.

FIG. 22 illustrates a process for parsing, splitting and/or separatingdata with encryption and storing the encryption master key separatelyfrom the data.

FIG. 23 illustrates the intermediary key process for parsing, splittingand/or separating data with encryption and storage of the encryptionmaster key with the data.

FIG. 24 illustrates the intermediary key process for parsing, splittingand/or separating data with encryption and storing the encryption masterkey separately from the data.

FIG. 25 illustrates utilization of the cryptographic methods and systemsof the present invention with a small working group.

FIG. 26 is a block diagram of an illustrative physical token securitysystem employing the secure data parser in accordance with oneembodiment of the present invention.

FIG. 27 is a block diagram of an illustrative arrangement in which thesecure data parser is integrated into a system in accordance with oneembodiment of the present invention.

FIG. 28 is a block diagram of an illustrative data in motion system inaccordance with one embodiment of the present invention.

FIG. 29 is a block diagram of another illustrative data in motion systemin accordance with one embodiment of the present invention.

FIGS. 30-32 are block diagrams of an illustrative system having thesecure data parser integrated in accordance with one embodiment of thepresent invention.

FIG. 33 is a process flow diagram of an illustrative process for parsingand splitting data in accordance with one embodiment of the presentinvention.

FIG. 34 is a process flow diagram of an illustrative process forrestoring portions of data into original data in accordance with oneembodiment of the present invention.

FIG. 35 is a process flow diagram of an illustrative process forsplitting data at the bit level in accordance with one embodiment of thepresent invention.

FIG. 36 is a process flow diagram of illustrative steps and features inaccordance with one embodiment of the present invention.

FIG. 37 is a process flow diagram of illustrative steps and features inaccordance with one embodiment of the present invention.

FIG. 38 is a simplified block diagram of the storage of key and datacomponents within shares in accordance with one embodiment of thepresent invention.

FIG. 39 is a simplified block diagram of the storage of key and datacomponents within shares using a workgroup key in accordance with oneembodiment of the present invention.

FIGS. 40A and 40B are simplified and illustrative process flow diagramsfor header generation and data splitting for data in motion inaccordance with one embodiment of the present invention.

FIG. 41 is a simplified block diagram of an illustrative share format inaccordance with one embodiment of the present invention.

FIGS. 42A-E are block diagrams depicting the operation of anillustrative secure sharing system in accordance with one embodiment ofthe present invention.

FIG. 43 illustrates an implementation in which a cryptographic sharingclient of a user device is configured to perform a combined sharingoperation to securely share a data set with a plurality of users inaccordance with one embodiment of the present invention.

FIG. 44 is a flow diagram of illustrative steps of a method for securelysharing data in accordance with one embodiment of the present invention.

FIG. 45 is a flow diagram of illustrative sub-steps that a processor mayperform in the course of performing step 4410 of FIG. 44, in accordancewith one embodiment of the present invention.

FIG. 46 is a flow diagram of illustrative steps of a method foraccessing a data set shared securely according to the method illustratedin FIG. 44, in accordance with one embodiment of the present invention.

FIG. 47 is a flow diagram of illustrative steps of a method for securelysharing data in accordance with one embodiment of the present invention.

DETAILED DESCRIPTION

The systems and methods described herein may be used in conjunction withother systems and methods described in commonly-owned U.S. Pat. No.7,391,865 and commonly-owned U.S. patent application Ser. No.11/258,839, filed Oct. 25, 2005, Ser. No. 11/602,667, filed Nov. 20,2006, Ser. No. 11/983,355, filed Nov. 7, 2007, Ser. No. 11/999,575,filed Dec. 5, 2007, Ser. No. 12/148,365, filed Apr. 18, 2008, Ser. No.12/209,703, filed Sep. 12, 2008, Ser. No. 12/349,897, filed Jan. 7,2009, Ser. No. 12/391,028, filed Feb. 23, 2009, Ser. No. 12/783,276,filed May 19, 2010, Ser. No. 12/953,877, filed Nov. 24, 2010, and U.S.Provisional Patent Application Nos. 61/436,991, filed Jan. 27, 2011,61/264,464, filed Nov. 25, 2009, 61/319,658, filed Mar. 31, 2010,61/320,242, filed Apr. 1, 2010, 61/349,560, filed May 28, 2010,61/373,187, filed Aug. 12, 2010, 61/374,950, filed Aug. 18, 2010, and61/384,583, filed Sep. 20, 2010. The disclosures of each of theaforementioned, earlier-filed applications are hereby incorporated byreference herein in their entireties.

One aspect of the present invention is to provide a cryptographic systemwhere one or more secure servers, or a trust engine, storescryptographic keys and user authentication data. Users access thefunctionality of conventional cryptographic systems through networkaccess to the trust engine, however, the trust engine does not releaseactual keys and other authentication data and therefore, the keys anddata remain secure. This server-centric storage of keys andauthentication data provides for user-independent security, portability,availability, and straightforwardness.

Because users can be confident in, or trust, the cryptographic system toperform user and document authentication and other cryptographicfunctions, a wide variety of functionality may be incorporated into thesystem. For example, the trust engine provider can ensure againstagreement repudiation by, for example, authenticating the agreementparticipants, digitally signing the agreement on behalf of or for theparticipants, and storing a record of the agreement digitally signed byeach participant. In addition, the cryptographic system may monitoragreements and determine to apply varying degrees of authentication,based on, for example, price, user, vendor, geographic location, placeof use, or the like.

To facilitate a complete understanding of the invention, the remainderof the detailed description describes the invention with reference tothe figures, wherein like elements are referenced with like numeralsthroughout.

FIG. 1 illustrates a block diagram of a cryptographic system 100,according to aspects of an embodiment of the invention. As shown in FIG.1, the cryptographic system 100 includes a user system 105, a trustengine 110, a certificate authority 115, and a vendor system 120,communicating through a communication link 125.

According to one embodiment of the invention, the user system 105comprises a conventional general-purpose computer having one or moremicroprocessors, such as, for example, an Intel-based processor.Moreover, the user system 105 includes an appropriate operating system,such as, for example, an operating system capable of including graphicsor windows, such as Windows, Unix, Linux, or the like. As shown in FIG.1, the user system 105 may include a biometric device 107. The biometricdevice 107 may advantageously capture a user's biometric and transferthe captured biometric to the trust engine 110. According to oneembodiment of the invention, the biometric device may advantageouslycomprise a device having attributes and features similar to thosedisclosed in U.S. patent application Ser. No. 08/926,277, filed on Sep.5, 1997, entitled “RELIEF OBJECT IMAGE GENERATOR,” U.S. patentapplication Ser. No. 09/558,634, filed on Apr. 26, 2000, entitled“IMAGING DEVICE FOR A RELIEF OBJECT AND SYSTEM AND METHOD OF USING THEIMAGE DEVICE,” U.S. patent application Ser. No. 09/435,011, filed onNov. 5, 1999, entitled “RELIEF OBJECT SENSOR ADAPTOR,” and U.S. patentapplication Ser. No. 09/477,943, filed on Jan. 5, 2000, entitled “PLANAROPTICAL IMAGE SENSOR AND SYSTEM FOR GENERATING AN ELECTRONIC IMAGE OF ARELIEF OBJECT FOR FINGERPRINT READING,” all of which are owned by theinstant assignee, and all of which are hereby incorporated by referenceherein.

In addition, the user system 105 may connect to the communication link125 through a conventional service provider, such as, for example, adial up, digital subscriber line (DSL), cable modem, fiber connection,or the like. According to another embodiment, the user system 105connects the communication link 125 through network connectivity suchas, for example, a local or wide area network. According to oneembodiment, the operating system includes a TCP/IP stack that handlesall incoming and outgoing message traffic passed over the communicationlink 125.

Although the user system 105 is disclosed with reference to theforegoing embodiments, the invention is not intended to be limitedthereby. Rather, a skilled artisan will recognize from the disclosureherein, a wide number of alternatives embodiments of the user system105, including almost any computing device capable of sending orreceiving information from another computer system. For example, theuser system 105 may include, but is not limited to, a computerworkstation, an interactive television, an interactive kiosk, a personalmobile computing device, such as a digital assistant, mobile phone,laptop, or the like, personal networking equipment, such as a homerouter, a network storage device (“NAS”), personal hotspot, or the like,or a wireless communications device, a smartcard, an embedded computingdevice, or the like, which can interact with the communication link 125.In such alternative systems, the operating systems will likely differand be adapted for the particular device. However, according to oneembodiment, the operating systems advantageously continue to provide theappropriate communications protocols needed to establish communicationwith the communication link 125.

FIG. 1 illustrates the trust engine 110. According to one embodiment,the trust engine 110 comprises one or more secure servers for accessingand storing sensitive information, which may be any type or form ofdata, such as, but not limited to text, audio, video, userauthentication data and public and private cryptographic keys. Accordingto one embodiment, the authentication data includes data designed touniquely identify a user of the cryptographic system 100. For example,the authentication data may include a user identification number, one ormore biometrics, and a series of questions and answers generated by thetrust engine 110 or the user, but answered initially by the user atenrollment. The foregoing questions may include demographic data, suchas place of birth, address, anniversary, or the like, personal data,such as mother's maiden name, favorite ice cream, or the like, or otherdata designed to uniquely identify the user. The trust engine 110compares a user's authentication data associated with a currenttransaction, to the authentication data provided at an earlier time,such as, for example, during enrollment. The trust engine 110 mayadvantageously require the user to produce the authentication data atthe time of each transaction, or, the trust engine 110 mayadvantageously allow the user to periodically produce authenticationdata, such as at the beginning of a string of transactions or thelogging onto a particular vendor website.

According to the embodiment where the user produces biometric data, theuser provides a physical characteristic, such as, but not limited to,facial scan, hand scan, ear scan, iris scan, retinal scan, vascularpattern, DNA, a fingerprint, writing or speech, to the biometric device107. The biometric device advantageously produces an electronic pattern,or biometric, of the physical characteristic. The electronic pattern istransferred through the user system 105 to the trust engine 110 foreither enrollment or authentication purposes.

Once the user produces the appropriate authentication data and the trustengine 110 determines a positive match between that authentication data(current authentication data) and the authentication data provided atthe time of enrollment (enrollment authentication data), the trustengine 110 provides the user with complete cryptographic functionality.For example, the properly authenticated user may advantageously employthe trust engine 110 to perform hashing, digitally signing, encryptingand decrypting (often together referred to only as encrypting), creatingor distributing digital certificates, and the like. However, the privatecryptographic keys used in the cryptographic functions will not beavailable outside the trust engine 110, thereby ensuring the integrityof the cryptographic keys.

According to one embodiment, the trust engine 110 generates and storescryptographic keys. According to another embodiment, at least onecryptographic key is associated with each user. Moreover, when thecryptographic keys include public-key technology, each private keyassociated with a user is generated within, and not released from, thetrust engine 110. Thus, so long as the user has access to the trustengine 110, the user may perform cryptographic functions using his orher private or public key. Such remote access advantageously allowsusers to remain completely mobile and access cryptographic functionalitythrough practically any Internet connection, such as cellular andsatellite phones, kiosks, laptops, hotel rooms and the like.

According to another embodiment, the trust engine 110 performs thecryptographic functionality using a key pair generated for the trustengine 110. According to this embodiment, the trust engine 110 firstauthenticates the user, and after the user has properly producedauthentication data matching the enrollment authentication data, thetrust engine 110 uses its own cryptographic key pair to performcryptographic functions on behalf of the authenticated user.

A skilled artisan will recognize from the disclosure herein that thecryptographic keys may advantageously include some or all of symmetrickeys, public keys, and private keys. In addition, a skilled artisan willrecognize from the disclosure herein that the foregoing keys may beimplemented with a wide number of algorithms available from commercialtechnologies, such as, for example, RSA, ELGAMAL, or the like.

FIG. 1 also illustrates the certificate authority 115. According to oneembodiment, the certificate authority 115 may advantageously comprise atrusted third-party organization or company that issues digitalcertificates, such as, for example, VeriSign, Baltimore, Entrust, or thelike. The trust engine 110 may advantageously transmit requests fordigital certificates, through one or more conventional digitalcertificate protocols, such as, for example, PKCS10, to the certificateauthority 115. In response, the certificate authority 115 will issue adigital certificate in one or more of a number of differing protocols,such as, for example, PKCS7. According to one embodiment of theinvention, the trust engine 110 requests digital certificates fromseveral or all of the prominent certificate authorities 115 such thatthe trust engine 110 has access to a digital certificate correspondingto the certificate standard of any requesting party.

According to another embodiment, the trust engine 110 internallyperforms certificate issuances. In this embodiment, the trust engine 110may access a certificate system for generating certificates and/or mayinternally generate certificates when they are requested, such as, forexample, at the time of key generation or in the certificate standardrequested at the time of the request. The trust engine 110 will bedisclosed in greater detail below.

FIG. 1 also illustrates the vendor system 120. According to oneembodiment, the vendor system 120 advantageously comprises a Web server.Typical Web servers generally serve content over the Internet using oneof several internet markup languages or document format standards, suchas the Hyper-Text Markup Language (HTML) or the Extensible MarkupLanguage (XML). The Web server accepts requests from browsers likeNetscape and Internet Explorer and then returns the appropriateelectronic documents. A number of server or client-side technologies canbe used to increase the power of the Web server beyond its ability todeliver standard electronic documents. For example, these technologiesinclude Common Gateway Interface (CGI) scripts, SSL security, and ActiveServer Pages (ASPs). The vendor system 120 may advantageously provideelectronic content relating to commercial, personal, educational, orother transactions.

Although the vendor system 120 is disclosed with reference to theforegoing embodiments, the invention is not intended to be limitedthereby. Rather, a skilled artisan will recognize from the disclosureherein that the vendor system 120 may advantageously comprise any of thedevices described with reference to the user system 105 or combinationthereof.

FIG. 1 also illustrates the communication link 125 connecting the usersystem 105, the trust engine 110, the certificate authority 115, and thevendor system 120. According to one embodiment, the communication link125 preferably comprises the Internet. The Internet, as used throughoutthis disclosure is a global network of computers. The structure of theInternet, which is well known to those of ordinary skill in the art,includes a network backbone with networks branching from the backbone.These branches, in turn, have networks branching from them, and so on.Routers move information packets between network levels, and then fromnetwork to network, until the packet reaches the neighborhood of itsdestination. From the destination, the destination network's hostdirects the information packet to the appropriate terminal, or node. Inone advantageous embodiment, the Internet routing hubs comprise domainname system (DNS) servers using Transmission Control Protocol/InternetProtocol (TCP/IP) as is well known in the art. The routing hubs connectto one or more other routing hubs via high-speed communication links.

One popular part of the Internet is the World Wide Web. The World WideWeb contains different computers, which store documents capable ofdisplaying graphical and textual information. The computers that provideinformation on the World Wide Web are typically called “websites.” Awebsite is defined by an Internet address that has an associatedelectronic page. The electronic page can be identified by a UniformResource Locator (URL). Generally, an electronic page is a document thatorganizes the presentation of text, graphical images, audio, video, andso forth.

Although the communication link 125 is disclosed in terms of itspreferred embodiment, one of ordinary skill in the art will recognizefrom the disclosure herein that the communication link 125 may include awide range of interactive communications links. For example, thecommunication link 125 may include interactive television networks,telephone networks, wireless data transmission systems, two-way cablesystems, customized private or public computer networks, interactivekiosk networks, automatic teller machine networks, direct links,satellite or cellular networks, and the like.

FIG. 2 illustrates a block diagram of the trust engine 110 of FIG. 1according to aspects of an embodiment of the invention. As shown in FIG.2, the trust engine 110 includes a transaction engine 205, a depository210, an authentication engine 215, and a cryptographic engine 220.According to one embodiment of the invention, the trust engine 110 alsoincludes mass storage 225. As further shown in FIG. 2, the transactionengine 205 communicates with the depository 210, the authenticationengine 215, and the cryptographic engine 220, along with the massstorage 225. In addition, the depository 210 communicates with theauthentication engine 215, the cryptographic engine 220, and the massstorage 225. Moreover, the authentication engine 215 communicates withthe cryptographic engine 220. According to one embodiment of theinvention, some or all of the foregoing communications mayadvantageously comprise the transmission of XML documents to IPaddresses that correspond to the receiving device. As mentioned in theforegoing, XML documents advantageously allow designers to create theirown customized document tags, enabling the definition, transmission,validation, and interpretation of data between applications and betweenorganizations. Moreover, some or all of the foregoing communications mayinclude conventional SSL technologies.

According to one embodiment, the transaction engine 205 comprises a datarouting device, such as a conventional Web server available fromNetscape, Microsoft, Apache, or the like. For example, the Web servermay advantageously receive incoming data from the communication link125. According to one embodiment of the invention, the incoming data isaddressed to a front-end security system for the trust engine 110. Forexample, the front-end security system may advantageously include afirewall, an intrusion detection system searching for known attackprofiles, and/or a virus scanner. After clearing the front-end securitysystem, the data is received by the transaction engine 205 and routed toone of the depository 210, the authentication engine 215, thecryptographic engine 220, and the mass storage 225. In addition, thetransaction engine 205 monitors incoming data from the authenticationengine 215 and cryptographic engine 220, and routes the data toparticular systems through the communication link 125. For example, thetransaction engine 205 may advantageously route data to the user system105, the certificate authority 115, or the vendor system 120.

According to one embodiment, the data is routed using conventional HTTProuting techniques, such as, for example, employing URLs or UniformResource Indicators (URIs). URIs are similar to URLs, however, URIstypically indicate the source of files or actions, such as, for example,executables, scripts, and the like. Therefore, according to the oneembodiment, the user system 105, the certificate authority 115, thevendor system 120, and the components of the trust engine 210,advantageously include sufficient data within communication URLs or URIsfor the transaction engine 205 to properly route data throughout thecryptographic system.

Although the data routing is disclosed with reference to its preferredembodiment, a skilled artisan will recognize a wide number of possibledata routing solutions or strategies. For example, XML or other datapackets may advantageously be unpacked and recognized by their format,content, or the like, such that the transaction engine 205 may properlyroute data throughout the trust engine 110. Moreover, a skilled artisanwill recognize that the data routing may advantageously be adapted tothe data transfer protocols conforming to particular network systems,such as, for example, when the communication link 125 comprises a localnetwork.

According to yet another embodiment of the invention, the transactionengine 205 includes conventional SSL encryption technologies, such thatthe foregoing systems may authenticate themselves, and vice versa, withtransaction engine 205, during particular communications. As will beused throughout this disclosure, the term “½ SSL” refers tocommunications where a server but not necessarily the client, is SSLauthenticated, and the term “FULL SSL” refers to communications wherethe client and the server are SSL authenticated. When the instantdisclosure uses the term “SSL”, the communication may comprise ½ or FULLSSL.

As the transaction engine 205 routes data to the various components ofthe cryptographic system 100, the transaction engine 205 mayadvantageously create an audit trail. According to one embodiment, theaudit trail includes a record of at least the type and format of datarouted by the transaction engine 205 throughout the cryptographic system100. Such audit data may advantageously be stored in the mass storage225.

FIG. 2 also illustrates the depository 210. According to one embodiment,the depository 210 comprises one or more data storage facilities, suchas, for example, a directory server, a database server, or the like. Asshown in FIG. 2, the depository 210 stores cryptographic keys andenrollment authentication data. The cryptographic keys mayadvantageously correspond to the trust engine 110 or to users of thecryptographic system 100, such as the user or vendor. The enrollmentauthentication data may advantageously include data designed to uniquelyidentify a user, such as, user ID, passwords, answers to questions,biometric data, or the like. This enrollment authentication data mayadvantageously be acquired at enrollment of a user or anotheralternative later time. For example, the trust engine 110 may includeperiodic or other renewal or reissue of enrollment authentication data.

According to one embodiment, the communication from the transactionengine 205 to and from the authentication engine 215 and thecryptographic engine 220 comprises secure communication, such as, forexample conventional SSL technology. In addition, as mentioned in theforegoing, the data of the communications to and from the depository 210may be transferred using URLs, URIs, HTTP or XML documents, with any ofthe foregoing advantageously having data requests and formats embeddedtherein.

As mentioned above, the depository 210 may advantageously comprises aplurality of secure data storage facilities. In such an embodiment, thesecure data storage facilities may be configured such that a compromiseof the security in one individual data storage facility will notcompromise the cryptographic keys or the authentication data storedtherein. For example, according to this embodiment, the cryptographickeys and the authentication data are mathematically operated on so as tostatistically and substantially randomize the data stored in each datastorage facility. According to one embodiment, the randomization of thedata of an individual data storage facility renders that dataundecipherable. Thus, compromise of an individual data storage facilityproduces only a randomized undecipherable number and does not compromisethe security of any cryptographic keys or the authentication data as awhole.

FIG. 2 also illustrates the trust engine 110 including theauthentication engine 215. According to one embodiment, theauthentication engine 215 comprises a data comparator configured tocompare data from the transaction engine 205 with data from thedepository 210. For example, during authentication, a user suppliescurrent authentication data to the trust engine 110 such that thetransaction engine 205 receives the current authentication data. Asmentioned in the foregoing, the transaction engine 205 recognizes thedata requests, preferably in the URL or URI, and routes theauthentication data to the authentication engine 215. Moreover, uponrequest, the depository 210 forwards enrollment authentication datacorresponding to the user to the authentication engine 215. Thus, theauthentication engine 215 has both the current authentication data andthe enrollment authentication data for comparison.

According to one embodiment, the communications to the authenticationengine comprise secure communications, such as, for example, SSLtechnology. Additionally, security can be provided within the trustengine 110 components, such as, for example, super-encryption usingpublic key technologies. For example, according to one embodiment, theuser encrypts the current authentication data with the public key of theauthentication engine 215. In addition, the depository 210 also encryptsthe enrollment authentication data with the public key of theauthentication engine 215. In this way, only the authentication engine'sprivate key can be used to decrypt the transmissions.

As shown in FIG. 2, the trust engine 110 also includes the cryptographicengine 220. According to one embodiment, the cryptographic enginecomprises a cryptographic handling module, configured to advantageouslyprovide conventional cryptographic functions, such as, for example,public-key infrastructure (PKI) functionality. For example, thecryptographic engine 220 may advantageously issue public and privatekeys for users of the cryptographic system 100. In this manner, thecryptographic keys are generated at the cryptographic engine 220 andforwarded to the depository 210 such that at least the privatecryptographic keys are not available outside of the trust engine 110.According to another embodiment, the cryptographic engine 220 randomizesand splits at least the private cryptographic key data, thereby storingonly the randomized split data. Similar to the splitting of theenrollment authentication data, the splitting process ensures the storedkeys are not available outside the cryptographic engine 220. Accordingto another embodiment, the functions of the cryptographic engine can becombined with and performed by the authentication engine 215.

According to one embodiment, communications to and from thecryptographic engine include secure communications, such as SSLtechnology. In addition, XML documents may advantageously be employed totransfer data and/or make cryptographic function requests.

FIG. 2 also illustrates the trust engine 110 having the mass storage225. As mentioned in the foregoing, the transaction engine 205 keepsdata corresponding to an audit trail and stores such data in the massstorage 225. Similarly, according to one embodiment of the invention,the depository 210 keeps data corresponding to an audit trail and storessuch data in the mass storage device 225. The depository audit traildata is similar to that of the transaction engine 205 in that the audittrail data comprises a record of the requests received by the depository210 and the response thereof. In addition, the mass storage 225 may beused to store digital certificates having the public key of a usercontained therein.

Although the trust engine 110 is disclosed with reference to itspreferred and alternative embodiments, the invention is not intended tobe limited thereby. Rather, a skilled artisan will recognize in thedisclosure herein, a wide number of alternatives for the trust engine110. For example, the trust engine 110, may advantageously perform onlyauthentication, or alternatively, only some or all of the cryptographicfunctions, such as data encryption and decryption. According to suchembodiments, one of the authentication engine 215 and the cryptographicengine 220 may advantageously be removed, thereby creating a morestraightforward design for the trust engine 110. In addition, thecryptographic engine 220 may also communicate with a certificateauthority such that the certificate authority is embodied within thetrust engine 110. According to yet another embodiment, the trust engine110 may advantageously perform authentication and one or morecryptographic functions, such as, for example, digital signing.

FIG. 3 illustrates a block diagram of the transaction engine 205 of FIG.2, according to aspects of an embodiment of the invention. According tothis embodiment, the transaction engine 205 comprises an operatingsystem 305 having a handling thread and a listening thread. Theoperating system 305 may advantageously be similar to those found inconventional high volume servers, such as, for example, Web serversavailable from Apache. The listening thread monitors the incomingcommunication from one of the communication link 125, the authenticationengine 215, and the cryptographic engine 220 for incoming data flow. Thehandling thread recognizes particular data structures of the incomingdata flow, such as, for example, the foregoing data structures, therebyrouting the incoming data to one of the communication link 125, thedepository 210, the authentication engine 215, the cryptographic engine220, or the mass storage 225. As shown in FIG. 3, the incoming andoutgoing data may advantageously be secured through, for example, SSLtechnology.

FIG. 4 illustrates a block diagram of the depository 210 of FIG. 2according to aspects of an embodiment of the invention. According tothis embodiment, the depository 210 comprises one or more lightweightdirectory access protocol (LDAP) servers. LDAP directory servers areavailable from a wide variety of manufacturers such as Netscape, ISO,and others. FIG. 4 also shows that the directory server preferablystores data 405 corresponding to the cryptographic keys and data 410corresponding to the enrollment authentication data. According to oneembodiment, the depository 210 comprises a single logical memorystructure indexing authentication data and cryptographic key data to aunique user ID. The single logical memory structure preferably includesmechanisms to ensure a high degree of trust, or security, in the datastored therein. For example, the physical location of the depository 210may advantageously include a wide number of conventional securitymeasures, such as limited employee access, modern surveillance systems,and the like. In addition to, or in lieu of, the physical securities,the computer system or server may advantageously include softwaresolutions to protect the stored data. For example, the depository 210may advantageously create and store data 415 corresponding to an audittrail of actions taken. In addition, the incoming and outgoingcommunications may advantageously be encrypted with public keyencryption coupled with conventional SSL technologies.

According to another embodiment, the depository 210 may comprisedistinct and physically separated data storage facilities, as disclosedfurther with reference to FIG. 7.

FIG. 5 illustrates a block diagram of the authentication engine 215 ofFIG. 2 according to aspects of an embodiment of the invention. Similarto the transaction engine 205 of FIG. 3, the authentication engine 215comprises an operating system 505 having at least a listening and ahandling thread of a modified version of a conventional Web server, suchas, for example, Web servers available from Apache. As shown in FIG. 5,the authentication engine 215 includes access to at least one privatekey 510. The private key 510 may advantageously be used for example, todecrypt data from the transaction engine 205 or the depository 210,which was encrypted with a corresponding public key of theauthentication engine 215.

FIG. 5 also illustrates the authentication engine 215 comprising acomparator 515, a data splitting module 520, and a data assemblingmodule 525. According to the preferred embodiment of the invention, thecomparator 515 includes technology capable of comparing potentiallycomplex patterns related to the foregoing biometric authentication data.The technology may include hardware, software, or combined solutions forpattern comparisons, such as, for example, those representing fingerprint patterns or voice patterns. In addition, according to oneembodiment, the comparator 515 of the authentication engine 215 mayadvantageously compare conventional hashes of documents in order torender a comparison result. According to one embodiment of theinvention, the comparator 515 includes the application of heuristics 530to the comparison. The heuristics 530 may advantageously addresscircumstances surrounding an authentication attempt, such as, forexample, the time of day, IP address or subnet mask, purchasing profile,email address, processor serial number or ID, or the like.

Moreover, the nature of biometric data comparisons may result in varyingdegrees of confidence being produced from the matching of currentbiometric authentication data to enrollment data. For example, unlike atraditional password which may only return a positive or negative match,a fingerprint may be determined to be a partial match, e.g. a 90% match,a 75% match, or a 10% match, rather than simply being correct orincorrect. Other biometric identifiers such as voice print analysis orface recognition may share this property of probabilisticauthentication, rather than absolute authentication.

When working with such probabilistic authentication or in other caseswhere an authentication is considered less than absolutely reliable, itis desirable to apply the heuristics 530 to determine whether the levelof confidence in the authentication provided is sufficiently high toauthenticate the transaction which is being made.

It will sometimes be the case that the transaction at issue is arelatively low value transaction where it is acceptable to beauthenticated to a lower level of confidence. This could include atransaction which has a low dollar value associated with it (e.g., a $10purchase) or a transaction with low risk (e.g., admission to amembers-only web site).

Conversely, for authenticating other transactions, it may be desirableto require a high degree of confidence in the authentication beforeallowing the transaction to proceed. Such transactions may includetransactions of large dollar value (e.g., signing a multi-million dollarsupply contract) or transaction with a high risk if an improperauthentication occurs (e.g., remotely logging onto a governmentcomputer).

The use of the heuristics 530 in combination with confidence levels andtransactions values may be used as will be described below to allow thecomparator to provide a dynamic context-sensitive authentication system.

According to another embodiment of the invention, the comparator 515 mayadvantageously track authentication attempts for a particulartransaction. For example, when a transaction fails, the trust engine 110may request the user to re-enter his or her current authentication data.The comparator 515 of the authentication engine 215 may advantageouslyemploy an attempt limiter 535 to limit the number of authenticationattempts, thereby prohibiting brute-force attempts to impersonate auser's authentication data. According to one embodiment, the attemptlimiter 535 comprises a software module monitoring transactions forrepeating authentication attempts and, for example, limiting theauthentication attempts for a given transaction to three. Thus, theattempt limiter 535 will limit an automated attempt to impersonate anindividual's authentication data to, for example, simply three“guesses.” Upon three failures, the attempt limiter 535 mayadvantageously deny additional authentication attempts. Such denial mayadvantageously be implemented through, for example, the comparator 515returning a negative result regardless of the current authenticationdata being transmitted. On the other hand, the transaction engine 205may advantageously block any additional authentication attemptspertaining to a transaction in which three attempts have previouslyfailed.

The authentication engine 215 also includes the data splitting module520 and the data assembling module 525. The data splitting module 520advantageously comprises a software, hardware, or combination modulehaving the ability to mathematically operate on various data so as tosubstantially randomize and split the data into portions. According toone embodiment, original data is not recreatable from an individualportion. The data assembling module 525 advantageously comprises asoftware, hardware, or combination module configured to mathematicallyoperate on the foregoing substantially randomized portions, such thatthe combination thereof provides the original deciphered data. Accordingto one embodiment, the authentication engine 215 employs the datasplitting module 520 to randomize and split enrollment authenticationdata into portions, and employs the data assembling module 525 toreassemble the portions into usable enrollment authentication data.

FIG. 6 illustrates a block diagram of the cryptographic engine 220 ofthe trust engine 200 of FIG. 2 according to aspects of one embodiment ofthe invention. Similar to the transaction engine 205 of FIG. 3, thecryptographic engine 220 comprises an operating system 605 having atleast a listening and a handling thread of a modified version of aconventional Web server, such as, for example, Web servers availablefrom Apache. As shown in FIG. 6, the cryptographic engine 220 comprisesa data splitting module 610 and a data assembling module 620 thatfunction similar to those of FIG. 5. However, according to oneembodiment, the data splitting module 610 and the data assembling module620 process cryptographic key data, as opposed to the foregoingenrollment authentication data. Although, a skilled artisan willrecognize from the disclosure herein that the data splitting module 910and the data splitting module 620 may be combined with those of theauthentication engine 215.

The cryptographic engine 220 also comprises a cryptographic handlingmodule 625 configured to perform one, some or all of a wide number ofcryptographic functions. According to one embodiment, the cryptographichandling module 625 may comprise software modules or programs, hardware,or both. According to another embodiment, the cryptographic handlingmodule 625 may perform data comparisons, data parsing, data splitting,data separating, data hashing, data encryption or decryption, digitalsignature verification or creation, digital certificate generation,storage, or requests, cryptographic key generation, or the like.Moreover, a skilled artisan will recognize from the disclosure hereinthat the cryptographic handling module 825 may advantageously comprisesa public-key infrastructure, such as Pretty Good Privacy (PGP), anRSA-based public-key system, or a wide number of alternative keymanagement systems. In addition, the cryptographic handling module 625may perform public-key encryption, symmetric-key encryption, or both. Inaddition to the foregoing, the cryptographic handling module 625 mayinclude one or more computer programs or modules, hardware, or both, forimplementing seamless, transparent, interoperability functions.

A skilled artisan will also recognize from the disclosure herein thatthe cryptographic functionality may include a wide number or variety offunctions generally relating to cryptographic key management systems.

FIG. 7 illustrates a simplified block diagram of a depository system 700according to aspects of an embodiment of the invention. As shown in FIG.7, the depository system 700 advantageously comprises multiple datastorage facilities, for example, data storage facilities D1, D2, D3, andD4. However, it is readily understood by those of ordinary skill in theart that the depository system may have only one data storage facility.According to one embodiment of the invention, each of the data storagefacilities D1 through D4 may advantageously comprise some or all of theelements disclosed with reference to the depository 210 of FIG. 4.Similar to the depository 210, the data storage facilities D1 through D4communicate with the transaction engine 205, the authentication engine215, and the cryptographic engine 220, preferably through conventionalSSL. Communication links transferring, for example, XML documents.Communications from the transaction engine 205 may advantageouslyinclude requests for data, wherein the request is advantageouslybroadcast to the IP address of each data storage facility D1 through D4.On the other hand, the transaction engine 205 may broadcast requests toparticular data storage facilities based on a wide number of criteria,such as, for example, response time, server loads, maintenanceschedules, or the like.

In response to requests for data from the transaction engine 205, thedepository system 700 advantageously forwards stored data to theauthentication engine 215 and the cryptographic engine 220. Therespective data assembling modules receive the forwarded data andassemble the data into useable formats. On the other hand,communications from the authentication engine 215 and the cryptographicengine 220 to the data storage facilities D1 through D4 may include thetransmission of sensitive data to be stored. For example, according toone embodiment, the authentication engine 215 and the cryptographicengine 220 may advantageously employ their respective data splittingmodules to divide sensitive data into undecipherable portions, and thentransmit one or more undecipherable portions of the sensitive data to aparticular data storage facility.

According to one embodiment, each data storage facility, D1 through D4,comprises a separate and independent storage system, such as, forexample, a directory server. According to another embodiment of theinvention, the depository system 700 comprises multiple geographicallyseparated independent data storage systems. By distributing thesensitive data into distinct and independent storage facilities D1through D4, some or all of which may be advantageously geographicallyseparated, the depository system 700 provides redundancy along withadditional security measures. For example, according to one embodiment,only data from two of the multiple data storage facilities, D1 throughD4, are needed to decipher and reassemble the sensitive data. Thus, asmany as two of the four data storage facilities D1 through D4 may beinoperative due to maintenance, system failure, power failure, or thelike, without affecting the functionality of the trust engine 110. Inaddition, because, according to one embodiment, the data stored in eachdata storage facility is randomized and undecipherable, compromise ofany individual data storage facility does not necessarily compromise thesensitive data. Moreover, in the embodiment having geographicalseparation of the data storage facilities, a compromise of multiplegeographically remote facilities becomes increasingly difficult. Infact, even a rogue employee will be greatly challenged to subvert theneeded multiple independent geographically remote data storagefacilities.

Although the depository system 700 is disclosed with reference to itspreferred and alternative embodiments, the invention is not intended tobe limited thereby. Rather, a skilled artisan will recognize from thedisclosure herein, a wide number of alternatives for the depositorysystem 700. For example, the depository system 700 may comprise one, twoor more data storage facilities. In addition, sensitive data may bemathematically operated such that portions from two or more data storagefacilities are needed to reassemble and decipher the sensitive data.

As mentioned in the foregoing, the authentication engine 215 and thecryptographic engine 220 each include a data splitting module 520 and610, respectively, for splitting any type or form of sensitive data,such as, for example, text, audio, video, the authentication data andthe cryptographic key data. FIG. 8 illustrates a flowchart of a datasplitting process 800 performed by the data splitting module accordingto aspects of an embodiment of the invention. As shown in FIG. 8, thedata splitting process 800 begins at step 805 when sensitive data “S” isreceived by the data splitting module of the authentication engine 215or the cryptographic engine 220. Preferably, in step 810, the datasplitting module then generates a substantially random number, value, orstring or set of bits, “A.” For example, the random number A may begenerated in a wide number of varying conventional techniques availableto one of ordinary skill in the art, for producing high quality randomnumbers suitable for use in cryptographic applications. In addition,according to one embodiment, the random number A comprises a bit lengthwhich may be any suitable length, such as shorter, longer or equal tothe bit length of the sensitive data, S.

In addition, in step 820 the data splitting process 800 generatesanother statistically random number “C.” According to the preferredembodiment, the generation of the statistically random numbers A and Cmay advantageously be done in parallel. The data splitting module thencombines the numbers A and C with the sensitive data S such that newnumbers “B” and “D” are generated. For example, number B may comprisethe binary combination of A XOR S and number D may comprise the binarycombination of C XOR S. The XOR function, or the “exclusive-or”function, is well known to those of ordinary skill in the art. Theforegoing combinations preferably occur in steps 825 and 830,respectively, and, according to one embodiment, the foregoingcombinations also occur in parallel. The data splitting process 800 thenproceeds to step 835 where the random numbers A and C and the numbers Band D are paired such that none of the pairings contain sufficient data,by themselves, to reorganize and decipher the original sensitive data S.For example, the numbers may be paired as follows: AC, AD, BC, and BD.According to one embodiment, each of the foregoing pairings isdistributed to one of the depositories D1 through D4 of FIG. 7.According to another embodiment, each of the foregoing pairings israndomly distributed to one of the depositories D1 through D4. Forexample, during a first data splitting process 800, the pairing AC maybe sent to depository D2, through, for example, a random selection ofD2's IP address. Then, during a second data splitting process 800, thepairing AC may be sent to depository D4, through, for example, a randomselection of D4's IP address. In addition, the pairings may all bestored on one depository, and may be stored in separate locations onsaid depository.

Based on the foregoing, the data splitting process 800 advantageouslyplaces portions of the sensitive data in each of the four data storagefacilities D1 through D4, such that no single data storage facility D1through D4 includes sufficient encrypted data to recreate the originalsensitive data S. As mentioned in the foregoing, such randomization ofthe data into individually unusable encrypted portions increasessecurity and provides for maintained trust in the data even if one ofthe data storage facilities, D1 through D4, is compromised.

Although the data splitting process 800 is disclosed with reference toits preferred embodiment, the invention is not intended to be limitedthereby. Rather a skilled artisan will recognize from the disclosureherein, a wide number of alternatives for the data splitting process800. For example, the data splitting process may advantageously splitthe data into two numbers, for example, random number A and number Band, randomly distribute A and B through two data storage facilities.Moreover, the data splitting process 800 may advantageously split thedata among a wide number of data storage facilities through generationof additional random numbers. The data may be split into any desired,selected, predetermined, or randomly assigned size unit, including butnot limited to, a bit, bits, bytes, kilobytes, megabytes or larger, orany combination or sequence of sizes. In addition, varying the sizes ofthe data units resulting from the splitting process may render the datamore difficult to restore to a useable form, thereby increasing securityof sensitive data. It is readily apparent to those of ordinary skill inthe art that the split data unit sizes may be a wide variety of dataunit sizes or patterns of sizes or combinations of sizes. For example,the data unit sizes may be selected or predetermined to be all of thesame size, a fixed set of different sizes, a combination of sizes, orrandomly generates sizes. Similarly, the data units may be distributedinto one or more shares according to a fixed or predetermined data unitsize, a pattern or combination of data unit sizes, or a randomlygenerated data unit size or sizes per share.

As mentioned in the foregoing, in order to recreate the sensitive dataS, the data portions need to be derandomized and reorganized. Thisprocess may advantageously occur in the data assembling modules, 525 and620, of the authentication engine 215 and the cryptographic engine 220,respectively. The data assembling module, for example, data assemblymodule 525, receives data portions from the data storage facilities D1through D4, and reassembles the data into useable form. For example,according to one embodiment where the data splitting module 520 employedthe data splitting process 800 of FIG. 8, the data assembling module 525uses data portions from at least two of the data storage facilities D1through D4 to recreate the sensitive data S. For example, the pairingsof AC, AD, BC, and BD, were distributed such that any two provide one ofA and B, or, C and D. Noting that S=A XOR B or S=C XOR D indicates thatwhen the data assembling module receives one of A and B, or, C and D,the data assembling module 525 can advantageously reassemble thesensitive data S. Thus, the data assembling module 525 may assemble thesensitive data S, when, for example, it receives data portions from atleast the first two of the data storage facilities D1 through D4 torespond to an assemble request by the trust engine 110.

Based on the above data splitting and assembling processes, thesensitive data S exists in usable format only in a limited area of thetrust engine 110. For example, when the sensitive data S includesenrollment authentication data, usable, nonrandomized enrollmentauthentication data is available only in the authentication engine 215.Likewise, when the sensitive data S includes private cryptographic keydata, usable, nonrandomized private cryptographic key data is availableonly in the cryptographic engine 220.

Although the data splitting and assembling processes are disclosed withreference to their preferred embodiments, the invention is not intendedto be limited thereby. Rather, a skilled artisan will recognize from thedisclosure herein, a wide number of alternatives for splitting andreassembling the sensitive data S. For example, public-key encryptionmay be used to further secure the data at the data storage facilities D1through D4. In addition, it is readily apparent to those of ordinaryskill in the art that the data splitting module described herein is alsoa separate and distinct embodiment of the present invention that may beincorporated into, combined with or otherwise made part of anypre-existing computer systems, software suites, database, orcombinations thereof, or other embodiments of the present invention,such as the trust engine, authentication engine, and transaction enginedisclosed and described herein.

FIG. 9A illustrates a data flow of an enrollment process 900 accordingto aspects of an embodiment of the invention. As shown in FIG. 9A, theenrollment process 900 begins at step 905 when a user desires to enrollwith the trust engine 110 of the cryptographic system 100. According tothis embodiment, the user system 105 advantageously includes aclient-side applet, such as a Java-based, that queries the user to enterenrollment data, such as demographic data and enrollment authenticationdata. According to one embodiment, the enrollment authentication dataincludes user ID, password(s), biometric(s), or the like. According toone embodiment, during the querying process, the client-side appletpreferably communicates with the trust engine 110 to ensure that achosen user ID is unique. When the user ID is nonunique, the trustengine 110 may advantageously suggest a unique user ID. The client-sideapplet gathers the enrollment data and transmits the enrollment data,for example, through and XML document, to the trust engine 110, and inparticular, to the transaction engine 205. According to one embodiment,the transmission is encoded with the public key of the authenticationengine 215.

According to one embodiment, the user performs a single enrollmentduring step 905 of the enrollment process 900. For example, the userenrolls himself or herself as a particular person, such as Joe User.When Joe User desires to enroll as Joe User, CEO of Mega Corp., thenaccording to this embodiment, Joe User enrolls a second time, receives asecond unique user ID and the trust engine 110 does not associate thetwo identities. According to another embodiment of the invention, theenrollment process 900 provides for multiple user identities for asingle user ID. Thus, in the above example, the trust engine 110 willadvantageously associate the two identities of Joe User. As will beunderstood by a skilled artisan from the disclosure herein, a user mayhave many identities, for example, Joe User the head of household, JoeUser the member of the Charitable Foundations, and the like. Even thoughthe user may have multiple identities, according to this embodiment, thetrust engine 110 preferably stores only one set of enrollment data.Moreover, users may advantageously add, edit/update, or deleteidentities as they are needed.

Although the enrollment process 900 is disclosed with reference to itspreferred embodiment, the invention is not intended to be limitedthereby. Rather, a skilled artisan will recognize from the disclosureherein, a wide number of alternatives for gathering of enrollment data,and in particular, enrollment authentication data. For example, theapplet may be common object model (COM) based applet or the like.

On the other hand, the enrollment process may include graded enrollment.For example, at a lowest level of enrollment, the user may enroll overthe communication link 125 without producing documentation as to his orher identity. According to an increased level of enrollment, the userenrolls using a trusted third party, such as a digital notary. Forexample, and the user may appear in person to the trusted third party,produce credentials such as a birth certificate, driver's license,military ID, or the like, and the trusted third party may advantageouslyinclude, for example, their digital signature in enrollment submission.The trusted third party may include an actual notary, a governmentagency, such as the Post Office or Department of Motor Vehicles, a humanresources person in a large company enrolling an employee, or the like.A skilled artisan will understand from the disclosure herein that a widenumber of varying levels of enrollment may occur during the enrollmentprocess 900.

After receiving the enrollment authentication data, at step 915, thetransaction engine 205, using conventional FULL SSL technology forwardsthe enrollment authentication data to the authentication engine 215. Instep 920, the authentication engine 215 decrypts the enrollmentauthentication data using the private key of the authentication engine215. In addition, the authentication engine 215 employs the datasplitting module to mathematically operate on the enrollmentauthentication data so as to split the data into at least twoindependently undecipherable, randomized, numbers. As mentioned in theforegoing, at least two numbers may comprise a statistically randomnumber and a binary XORed number. In step 925, the authentication engine215 forwards each portion of the randomized numbers to one of the datastorage facilities D1 through D4. As mentioned in the foregoing, theauthentication engine 215 may also advantageously randomize whichportions are transferred to which depositories.

Often during the enrollment process 900, the user will also desire tohave a digital certificate issued such that he or she may receiveencrypted documents from others outside the cryptographic system 100. Asmentioned in the foregoing, the certificate authority 115 generallyissues digital certificates according to one or more of severalconventional standards. Generally, the digital certificate includes apublic key of the user or system, which is known to everyone.

Whether the user requests a digital certificate at enrollment, or atanother time, the request is transferred through the trust engine 110 tothe authentication engine 215. According to one embodiment, the requestincludes an XML document having, for example, the proper name of theuser. According to step 935, the authentication engine 215 transfers therequest to the cryptographic engine 220 instructing the cryptographicengine 220 to generate a cryptographic key or key pair.

Upon request, at step 935, the cryptographic engine 220 generates atleast one cryptographic key. According to one embodiment, thecryptographic handling module 625 generates a key pair, where one key isused as a private key, and one is used as a public key. Thecryptographic engine 220 stores the private key and, according to oneembodiment, a copy of the public key. In step 945, the cryptographicengine 220 transmits a request for a digital certificate to thetransaction engine 205. According to one embodiment, the requestadvantageously includes a standardized request, such as PKCS10, embeddedin, for example, an XML document. The request for a digital certificatemay advantageously correspond to one or more certificate authorities andthe one or more standard formats the certificate authorities require.

In step 950 the transaction engine 205 forwards this request to thecertificate authority 115, who, in step 955, returns a digitalcertificate. The return digital certificate may advantageously be in astandardized format, such as PKCS7, or in a proprietary format of one ormore of the certificate authorities 115. In step 960, the digitalcertificate is received by the transaction engine 205, and a copy isforwarded to the user and a copy is stored with the trust engine 110.The trust engine 110 stores a copy of the certificate such that thetrust engine 110 will not need to rely on the availability of thecertificate authority 115. For example, when the user desires to send adigital certificate, or a third party requests the user's digitalcertificate, the request for the digital certificate is typically sentto the certificate authority 115. However, if the certificate authority115 is conducting maintenance or has been victim of a failure orsecurity compromise, the digital certificate may not be available.

At any time after issuing the cryptographic keys, the cryptographicengine 220 may advantageously employ the data splitting process 800described above such that the cryptographic keys are split intoindependently undecipherable randomized numbers. Similar to theauthentication data, at step 965 the cryptographic engine 220 transfersthe randomized numbers to the data storage facilities D1 through D4.

A skilled artisan will recognize from the disclosure herein that theuser may request a digital certificate anytime after enrollment.Moreover, the communications between systems may advantageously includeFULL SSL or public-key encryption technologies. Moreover, the enrollmentprocess may issue multiple digital certificates from multiplecertificate authorities, including one or more proprietary certificateauthorities internal or external to the trust engine 110.

As disclosed in steps 935 through 960, one embodiment of the inventionincludes the request for a certificate that is eventually stored on thetrust engine 110. Because, according to one embodiment, thecryptographic handling module 625 issues the keys used by the trustengine 110, each certificate corresponds to a private key. Therefore,the trust engine 110 may advantageously provide for interoperabilitythrough monitoring the certificates owned by, or associated with, auser. For example, when the cryptographic engine 220 receives a requestfor a cryptographic function, the cryptographic handling module 625 mayinvestigate the certificates owned by the requesting user to determinewhether the user owns a private key matching the attributes of therequest. When such a certificate exists, the cryptographic handlingmodule 625 may use the certificate or the public or private keysassociated therewith, to perform the requested function. When such acertificate does not exist, the cryptographic handling module 625 mayadvantageously and transparently perform a number of actions to attemptto remedy the lack of an appropriate key. For example, FIG. 9Billustrates a flowchart of an interoperability process 970, whichaccording to aspects of an embodiment of the invention, discloses theforegoing steps to ensure the cryptographic handling module 625 performscryptographic functions using appropriate keys.

As shown in FIG. 9B, the interoperability process 970 begins with step972 where the cryptographic handling module 925 determines the type ofcertificate desired. According to one embodiment of the invention, thetype of certificate may advantageously be specified in the request forcryptographic functions, or other data provided by the requestor.According to another embodiment, the certificate type may be ascertainedby the data format of the request. For example, the cryptographichandling module 925 may advantageously recognize the request correspondsto a particular type.

According to one embodiment, the certificate type may include one ormore algorithm standards, for example, RSA, ELGAMAL, or the like. Inaddition, the certificate type may include one or more key types, suchas symmetric keys, public keys, strong encryption keys such as 256 bitkeys, less secure keys, or the like. Moreover, the certificate type mayinclude upgrades or replacements of one or more of the foregoingalgorithm standards or keys, one or more message or data formats, one ormore data encapsulation or encoding schemes, such as Base 32 or Base 64.The certificate type may also include compatibility with one or morethird-party cryptographic applications or interfaces, one or morecommunication protocols, or one or more certificate standards orprotocols. A skilled artisan will recognize from the disclosure hereinthat other differences may exist in certificate types, and translationsto and from those differences may be implemented as disclosed herein.

Once the cryptographic handling module 625 determines the certificatetype, the interoperability process 970 proceeds to step 974, anddetermines whether the user owns a certificate matching the typedetermined in step 974. When the user owns a matching certificate, forexample, the trust engine 110 has access to the matching certificatethrough, for example, prior storage thereof, the cryptographic handlingmodule 825 knows that a matching private key is also stored within thetrust engine 110. For example, the matching private key may be storedwithin the depository 210 or depository system 700. The cryptographichandling module 625 may advantageously request the matching private keybe assembled from, for example, the depository 210, and then in step976, use the matching private key to perform cryptographic actions orfunctions. For example, as mentioned in the foregoing, the cryptographichandling module 625 may advantageously perform hashing, hashcomparisons, data encryption or decryption, digital signatureverification or creation, or the like.

When the user does not own a matching certificate, the interoperabilityprocess 970 proceeds to step 978 where the cryptographic handling module625 determines whether the users owns a cross-certified certificate.According to one embodiment, cross-certification between certificateauthorities occurs when a first certificate authority determines totrust certificates from a second certificate authority. In other words,the first certificate authority determines that certificates from thesecond certificate authority meets certain quality standards, andtherefore, may be “certified” as equivalent to the first certificateauthority's own certificates. Cross-certification becomes more complexwhen the certificate authorities issue, for example, certificates havinglevels of trust. For example, the first certificate authority mayprovide three levels of trust for a particular certificate, usuallybased on the degree of reliability in the enrollment process, while thesecond certificate authority may provide seven levels of trust.Cross-certification may advantageously track which levels and whichcertificates from the second certificate authority may be substitutedfor which levels and which certificates from the first. When theforegoing cross-certification is done officially and publicly betweentwo certification authorities, the mapping of certificates and levels toone another is often called “chaining.”

According to another embodiment of the invention, the cryptographichandling module 625 may advantageously develop cross-certificationsoutside those agreed upon by the certificate authorities. For example,the cryptographic handling module 625 may access a first certificateauthority's certificate practice statement (CPS), or other publishedpolicy statement, and using, for example, the authentication tokensrequired by particular trust levels, match the first certificateauthority's certificates to those of another certificate authority.

When, in step 978, the cryptographic handling module 625 determines thatthe users owns a cross-certified certificate, the interoperabilityprocess 970 proceeds to step 976, and performs the cryptographic actionor function using the cross-certified public key, private key, or both.Alternatively, when the cryptographic handling module 625 determinesthat the users does not own a cross-certified certificate, theinteroperability process 970 proceeds to step 980, where thecryptographic handling module 625 selects a certificate authority thatissues the requested certificate type, or a certificate cross-certifiedthereto. In step 982, the cryptographic handling module 625 determineswhether the user enrollment authentication data, discussed in theforegoing, meets the authentication requirements of the chosencertificate authority. For example, if the user enrolled over a networkby, for example, answering demographic and other questions, theauthentication data provided may establish a lower level of trust than auser providing biometric data and appearing before a third-party, suchas, for example, a notary. According to one embodiment, the foregoingauthentication requirements may advantageously be provided in the chosenauthentication authority's CPS.

When the user has provided the trust engine 110 with enrollmentauthentication data meeting the requirements of chosen certificateauthority, the interoperability process 970 proceeds to step 984, wherethe cryptographic handling module 825 acquires the certificate from thechosen certificate authority. According to one embodiment, thecryptographic handling module 625 acquires the certificate by followingsteps 945 through 960 of the enrollment process 900. For example, thecryptographic handling module 625 may advantageously employ one or morepublic keys from one or more of the key pairs already available to thecryptographic engine 220, to request the certificate from thecertificate authority. According to another embodiment, thecryptographic handling module 625 may advantageously generate one ormore new key pairs, and use the public keys corresponding thereto, torequest the certificate from the certificate authority.

According to another embodiment, the trust engine 110 may advantageouslyinclude one or more certificate issuing modules capable of issuing oneor more certificate types. According to this embodiment, the certificateissuing module may provide the foregoing certificate. When thecryptographic handling module 625 acquires the certificate, theinteroperability process 970 proceeds to step 976, and performs thecryptographic action or function using the public key, private key, orboth corresponding to the acquired certificate.

When the user, in step 982, has not provided the trust engine 110 withenrollment authentication data meeting the requirements of chosencertificate authority, the cryptographic handling module 625 determines,in step 986 whether there are other certificate authorities that havedifferent authentication requirements. For example, the cryptographichandling module 625 may look for certificate authorities having lowerauthentication requirements, but still issue the chosen certificates, orcross-certifications thereof.

When the foregoing certificate authority having lower requirementsexists, the interoperability process 970 proceeds to step 980 andchooses that certificate authority. Alternatively, when no suchcertificate authority exists, in step 988, the trust engine 110 mayrequest additional authentication tokens from the user. For example, thetrust engine 110 may request new enrollment authentication datacomprising, for example, biometric data. Also, the trust engine 110 mayrequest the user appear before a trusted third party and provideappropriate authenticating credentials, such as, for example, appearingbefore a notary with a drivers license, social security card, bank card,birth certificate, military ID, or the like. When the trust engine 110receives updated authentication data, the interoperability process 970proceeds to step 984 and acquires the foregoing chosen certificate.

Through the foregoing interoperability process 970, the cryptographichandling module 625 advantageously provides seamless, transparent,translations and conversions between differing cryptographic systems. Askilled artisan will recognize from the disclosure herein, a wide numberof advantages and implementations of the foregoing interoperable system.For example, the foregoing step 986 of the interoperability process 970may advantageously include aspects of trust arbitrage, discussed infurther detail below, where the certificate authority may under specialcircumstances accept lower levels of cross-certification. In addition,the interoperability process 970 may include ensuring interoperabilitybetween and employment of standard certificate revocations, such asemploying certificate revocation lists (CRL), online certificate statusprotocols (OCSP), or the like.

FIG. 10 illustrates a data flow of an authentication process 1000according to aspects of an embodiment of the invention. According to oneembodiment, the authentication process 1000 includes gathering currentauthentication data from a user and comparing that to the enrollmentauthentication data of the user. For example, the authentication process1000 begins at step 1005 where a user desires to perform a transactionwith, for example, a vendor. Such transactions may include, for example,selecting a purchase option, requesting access to a restricted area ordevice of the vendor system 120, or the like. At step 1010, a vendorprovides the user with a transaction ID and an authentication request.The transaction ID may advantageously include a 192 bit quantity havinga 32 bit timestamp concatenated with a 128 bit random quantity, or a“nonce,” concatenated with a 32 bit vendor specific constant. Such atransaction ID uniquely identifies the transaction such that copycattransactions can be refused by the trust engine 110.

The authentication request may advantageously include what level ofauthentication is needed for a particular transaction. For example, thevendor may specify a particular level of confidence that is required forthe transaction at issue. If authentication cannot be made to this levelof confidence, as will be discussed below, the transaction will notoccur without either further authentication by the user to raise thelevel of confidence, or a change in the terms of the authenticationbetween the vendor and the server. These issues are discussed morecompletely below.

According to one embodiment, the transaction ID and the authenticationrequest may be advantageously generated by a vendor-side applet or othersoftware program. In addition, the transmission of the transaction IDand authentication data may include one or more XML documents encryptedusing conventional SSL technology, such as, for example, ½ SSL, or, inother words vendor-side authenticated SSL.

After the user system 105 receives the transaction ID and authenticationrequest, the user system 105 gathers the current authentication data,potentially including current biometric information, from the user. Theuser system 105, at step 1015, encrypts at least the currentauthentication data “B” and the transaction ID, with the public key ofthe authentication engine 215, and transfers that data to the trustengine 110. The transmission preferably comprises XML documentsencrypted with at least conventional ½ SSL technology. In step 1020, thetransaction engine 205 receives the transmission, preferably recognizesthe data format or request in the URL or URI, and forwards thetransmission to the authentication engine 215.

During steps 1015 and 1020, the vendor system 120, at step 1025,forwards the transaction ID and the authentication request to the trustengine 110, using the preferred FULL SSL technology. This communicationmay also include a vendor ID, although vendor identification may also becommunicated through a non-random portion of the transaction ID. Atsteps 1030 and 1035, the transaction engine 205 receives thecommunication, creates a record in the audit trail, and generates arequest for the user's enrollment authentication data to be assembledfrom the data storage facilities D1 through D4. At step 1040, thedepository system 700 transfers the portions of the enrollmentauthentication data corresponding to the user to the authenticationengine 215. At step 1045, the authentication engine 215 decrypts thetransmission using its private key and compares the enrollmentauthentication data to the current authentication data provided by theuser.

The comparison of step 1045 may advantageously apply heuristical contextsensitive authentication, as referred to in the forgoing, and discussedin further detail below. For example, if the biometric informationreceived does not match perfectly, a lower confidence match results. Inparticular embodiments, the level of confidence of the authentication isbalanced against the nature of the transaction and the desires of boththe user and the vendor. Again, this is discussed in greater detailbelow.

At step 1050, the authentication engine 215 fills in the authenticationrequest with the result of the comparison of step 1045. According to oneembodiment of the invention, the authentication request is filled with aYES/NO or TRUE/FALSE result of the authentication process 1000. In step1055 the filled-in authentication request is returned to the vendor forthe vendor to act upon, for example, allowing the user to complete thetransaction that initiated the authentication request. According to oneembodiment, a confirmation message is passed to the user.

Based on the foregoing, the authentication process 1000 advantageouslykeeps sensitive data secure and produces results configured to maintainthe integrity of the sensitive data. For example, the sensitive data isassembled only inside the authentication engine 215. For example, theenrollment authentication data is undecipherable until it is assembledin the authentication engine 215 by the data assembling module, and thecurrent authentication data is undecipherable until it is unwrapped bythe conventional SSL technology and the private key of theauthentication engine 215. Moreover, the authentication resulttransmitted to the vendor does not include the sensitive data, and theuser may not even know whether he or she produced valid authenticationdata.

Although the authentication process 1000 is disclosed with reference toits preferred and alternative embodiments, the invention is not intendedto be limited thereby. Rather, a skilled artisan will recognize from thedisclosure herein, a wide number of alternatives for the authenticationprocess 1000. For example, the vendor may advantageously be replaced byalmost any requesting application, even those residing with the usersystem 105. For example, a client application, such as Microsoft Word,may use an application program interface (API) or a cryptographic API(CAPI) to request authentication before unlocking a document.Alternatively, a mail server, a network, a cellular phone, a personal ormobile computing device, a workstation, or the like, may all makeauthentication requests that can be filled by the authentication process1000. In fact, after providing the foregoing trusted authenticationprocess 1000, the requesting application or device may provide access toor use of a wide number of electronic or computer devices or systems.

Moreover, the authentication process 1000 may employ a wide number ofalternative procedures in the event of authentication failure. Forexample, authentication failure may maintain the same transaction ID andrequest that the user reenter his or her current authentication data. Asmentioned in the foregoing, use of the same transaction ID allows thecomparator of the authentication engine 215 to monitor and limit thenumber of authentication attempts for a particular transaction, therebycreating a more secure cryptographic system 100.

In addition, the authentication process 1000 may be advantageously beemployed to develop elegant single sign-on solutions, such as, unlockinga sensitive data vault. For example, successful or positiveauthentication may provide the authenticated user the ability toautomatically access any number of passwords for an almost limitlessnumber of systems and applications. For example, authentication of auser may provide the user access to password, login, financialcredentials, or the like, associated with multiple online vendors, alocal area network, various personal computing devices, Internet serviceproviders, auction providers, investment brokerages, or the like. Byemploying a sensitive data vault, users may choose truly large andrandom passwords because they no longer need to remember them throughassociation. Rather, the authentication process 1000 provides accessthereto. For example, a user may choose a random alphanumeric stringthat is twenty plus digits in length rather than something associatedwith a memorable data, name, etc.

According to one embodiment, a sensitive data vault associated with agiven user may advantageously be stored in the data storage facilitiesof the depository 210, or split and stored in the depository system 700.According to this embodiment, after positive user authentication, thetrust engine 110 serves the requested sensitive data, such as, forexample, to the appropriate password to the requesting application.According to another embodiment, the trust engine 110 may include aseparate system for storing the sensitive data vault. For example, thetrust engine 110 may include a stand-alone software engine implementingthe data vault functionality and figuratively residing “behind” theforegoing front-end security system of the trust engine 110. Accordingto this embodiment, the software engine serves the requested sensitivedata after the software engine receives a signal indicating positiveuser authentication from the trust engine 110.

In yet another embodiment, the data vault may be implemented by athird-party system. Similar to the software engine embodiment, thethird-party system may advantageously serve the requested sensitive dataafter the third-party system receives a signal indicating positive userauthentication from the trust engine 110. According to yet anotherembodiment, the data vault may be implemented on the user system 105. Auser-side software engine may advantageously serve the foregoing dataafter receiving a signal indicating positive user authentication fromthe trust engine 110.

Although the foregoing data vaults are disclosed with reference toalternative embodiments, a skilled artisan will recognize from thedisclosure herein, a wide number of additional implementations thereof.For example, a particular data vault may include aspects from some orall of the foregoing embodiments. In addition, any of the foregoing datavaults may employ one or more authentication requests at varying times.For example, any of the data vaults may require authentication every oneor more transactions, periodically, every one or more sessions, everyaccess to one or more Webpages or Websites, at one or more otherspecified intervals, or the like.

FIG. 11 illustrates a data flow of a signing process 1100 according toaspects of an embodiment of the invention. As shown in FIG. 11, thesigning process 1100 includes steps similar to those of theauthentication process 1000 described in the foregoing with reference toFIG. 10. According to one embodiment of the invention, the signingprocess 1100 first authenticates the user and then performs one or moreof several digital signing functions as will be discussed in furtherdetail below. According to another embodiment, the signing process 1100may advantageously store data related thereto, such as hashes ofmessages or documents, or the like. This data may advantageously be usedin an audit or any other event, such as for example, when aparticipating party attempts to repudiate a transaction.

As shown in FIG. 11, during the authentication steps, the user andvendor may advantageously agree on a message, such as, for example, acontract. During signing, the signing process 1100 advantageouslyensures that the contract signed by the user is identical to thecontract supplied by the vendor. Therefore, according to one embodiment,during authentication, the vendor and the user include a hash of theirrespective copies of the message or contract, in the data transmitted tothe authentication engine 215. By employing only a hash of a message orcontract, the trust engine 110 may advantageously store a significantlyreduced amount of data, providing for a more efficient and costeffective cryptographic system. In addition, the stored hash may beadvantageously compared to a hash of a document in question to determinewhether the document in question matches one signed by any of theparties. The ability to determine whether the document is identical toone relating to a transaction provides for additional evidence that canbe used against a claim for repudiation by a party to a transaction.

In step 1103, the authentication engine 215 assembles the enrollmentauthentication data and compares it to the current authentication dataprovided by the user. When the comparator of the authentication engine215 indicates that the enrollment authentication data matches thecurrent authentication data, the comparator of the authentication engine215 also compares the hash of the message supplied by the vendor to thehash of the message supplied by the user. Thus, the authenticationengine 215 advantageously ensures that the message agreed to by the useris identical to that agreed to by the vendor.

In step 1105, the authentication engine 215 transmits a digitalsignature request to the cryptographic engine 220. According to oneembodiment of the invention, the request includes a hash of the messageor contract. However, a skilled artisan will recognize from thedisclosure herein that the cryptographic engine 220 may encryptvirtually any type of data, including, but not limited to, video, audio,biometrics, images or text to form the desired digital signature.Returning to step 1105, the digital signature request preferablycomprises an XML document communicated through conventional SSLtechnologies.

In step 1110, the authentication engine 215 transmits a request to eachof the data storage facilities D1 through D4, such that each of the datastorage facilities D1 through D4 transmit their respective portion ofthe cryptographic key or keys corresponding to a signing party.According to another embodiment, the cryptographic engine 220 employssome or all of the steps of the interoperability process 970 discussedin the foregoing, such that the cryptographic engine 220 firstdetermines the appropriate key or keys to request from the depository210 or the depository system 700 for the signing party, and takesactions to provide appropriate matching keys. According to still anotherembodiment, the authentication engine 215 or the cryptographic engine220 may advantageously request one or more of the keys associated withthe signing party and stored in the depository 210 or depository system700.

According to one embodiment, the signing party includes one or both theuser and the vendor. In such case, the authentication engine 215advantageously requests the cryptographic keys corresponding to the userand/or the vendor. According to another embodiment, the signing partyincludes the trust engine 110. In this embodiment, the trust engine 110is certifying that the authentication process 1000 properlyauthenticated the user, vendor, or both. Therefore, the authenticationengine 215 requests the cryptographic key of the trust engine 110, suchas, for example, the key belonging to the cryptographic engine 220, toperform the digital signature. According to another embodiment, thetrust engine 110 performs a digital notary-like function. In thisembodiment, the signing party includes the user, vendor, or both, alongwith the trust engine 110. Thus, the trust engine 110 provides thedigital signature of the user and/or vendor, and then indicates with itsown digital signature that the user and/or vendor were properlyauthenticated. In this embodiment, the authentication engine 215 mayadvantageously request assembly of the cryptographic keys correspondingto the user, the vendor, or both. According to another embodiment, theauthentication engine 215 may advantageously request assembly of thecryptographic keys corresponding to the trust engine 110.

According to another embodiment, the trust engine 110 performs power ofattorney-like functions. For example, the trust engine 110 may digitallysign the message on behalf of a third party. In such case, theauthentication engine 215 requests the cryptographic keys associatedwith the third party. According to this embodiment, the signing process1100 may advantageously include authentication of the third party,before allowing power of attorney-like functions. In addition, theauthentication process 1000 may include a check for third partyconstraints, such as, for example, business logic or the like dictatingwhen and in what circumstances a particular third-party's signature maybe used.

Based on the foregoing, in step 1110, the authentication enginerequested the cryptographic keys from the data storage facilities D1through D4 corresponding to the signing party. In step 1115, the datastorage facilities D1 through D4 transmit their respective portions ofthe cryptographic key corresponding to the signing party to thecryptographic engine 220. According to one embodiment, the foregoingtransmissions include SSL technologies. According to another embodiment,the foregoing transmissions may advantageously be super-encrypted withthe public key of the cryptographic engine 220.

In step 1120, the cryptographic engine 220 assembles the foregoingcryptographic keys of the signing party and encrypts the messagetherewith, thereby forming the digital signature(s). In step 1125 of thesigning process 1100, the cryptographic engine 220 transmits the digitalsignature(s) to the authentication engine 215. In step 1130, theauthentication engine 215 transmits the filled-in authentication requestalong with a copy of the hashed message and the digital signature(s) tothe transaction engine 205. In step 1135, the transaction engine 205transmits a receipt comprising the transaction ID, an indication ofwhether the authentication was successful, and the digital signature(s),to the vendor. According to one embodiment, the foregoing transmissionmay advantageously include the digital signature of the trust engine110. For example, the trust engine 110 may encrypt the hash of thereceipt with its private key, thereby forming a digital signature to beattached to the transmission to the vendor.

According to one embodiment, the transaction engine 205 also transmits aconfirmation message to the user. Although the signing process 1100 isdisclosed with reference to its preferred and alternative embodiments,the invention is not intended to be limited thereby. Rather, a skilledartisan will recognize from the disclosure herein, a wide number ofalternatives for the signing process 1100. For example, the vendor maybe replaced with a user application, such as an email application. Forexample, the user may wish to digitally sign a particular email with hisor her digital signature. In such an embodiment, the transmissionthroughout the signing process 1100 may advantageously include only onecopy of a hash of the message. Moreover, a skilled artisan willrecognize from the disclosure herein that a wide number of clientapplications may request digital signatures. For example, the clientapplications may comprise word processors, spreadsheets, emails,voicemail, access to restricted system areas, or the like.

In addition, a skilled artisan will recognize from the disclosure hereinthat steps 1105 through 1120 of the signing process 1100 mayadvantageously employ some or all of the steps of the interoperabilityprocess 970 of FIG. 9B, thereby providing interoperability betweendiffering cryptographic systems that may, for example, need to processthe digital signature under differing signature types.

FIG. 12 illustrates a data flow of an encryption/decryption process 1200according to aspects of an embodiment of the invention. As shown in FIG.12, the decryption process 1200 begins by authenticating the user usingthe authentication process 1000. According to one embodiment, theauthentication process 1000 includes in the authentication request, asynchronous session key. For example, in conventional PKI technologies,it is understood by skilled artisans that encrypting or decrypting datausing public and private keys is mathematically intensive and mayrequire significant system resources. However, in symmetric keycryptographic systems, or systems where the sender and receiver of amessage share a single common key that is used to encrypt and decrypt amessage, the mathematical operations are significantly simpler andfaster. Thus, in the conventional PKI technologies, the sender of amessage will generate synchronous session key, and encrypt the messageusing the simpler, faster symmetric key system. Then, the sender willencrypt the session key with the public key of the receiver. Theencrypted session key will be attached to the synchronously encryptedmessage and both data are sent to the receiver. The receiver uses his orher private key to decrypt the session key, and then uses the sessionkey to decrypt the message. Based on the foregoing, the simpler andfaster symmetric key system is used for the majority of theencryption/decryption processing. Thus, in the decryption process 1200,the decryption advantageously assumes that a synchronous key has beenencrypted with the public key of the user. Thus, as mentioned in theforegoing, the encrypted session key is included in the authenticationrequest.

Returning to the decryption process 1200, after the user has beenauthenticated in step 1205, the authentication engine 215 forwards theencrypted session key to the cryptographic engine 220. In step 1210, theauthentication engine 215 forwards a request to each of the data storagefacilities, D1 through D4, requesting the cryptographic key data of theuser. In step 1215, each data storage facility, D1 through D4, transmitstheir respective portion of the cryptographic key to the cryptographicengine 220. According to one embodiment, the foregoing transmission isencrypted with the public key of the cryptographic engine 220.

In step 1220 of the decryption process 1200, the cryptographic engine220 assembles the cryptographic key and decrypts the session keytherewith. In step 1225, the cryptographic engine forwards the sessionkey to the authentication engine 215. In step 1227, the authenticationengine 215 fills in the authentication request including the decryptedsession key, and transmits the filled-in authentication request to thetransaction engine 205. In step 1230, the transaction engine 205forwards the authentication request along with the session key to therequesting application or vendor. Then, according to one embodiment, therequesting application or vendor uses the session key to decrypt theencrypted message.

Although the decryption process 1200 is disclosed with reference to itspreferred and alternative embodiments, a skilled artisan will recognizefrom the disclosure herein, a wide number of alternatives for thedecryption process 1200. For example, the decryption process 1200 mayforego synchronous key encryption and rely on full public-keytechnology. In such an embodiment, the requesting application maytransmit the entire message to the cryptographic engine 220, or, mayemploy some type of compression or reversible hash in order to transmitthe message to the cryptographic engine 220. A skilled artisan will alsorecognize from the disclosure herein that the foregoing communicationsmay advantageously include XML documents wrapped in SSL technology.

The encryption/decryption process 1200 also provides for encryption ofdocuments or other data. Thus, in step 1235, a requesting application orvendor may advantageously transmit to the transaction engine 205 of thetrust engine 110, a request for the public key of the user. Therequesting application or vendor makes this request because therequesting application or vendor uses the public key of the user, forexample, to encrypt the session key that will be used to encrypt thedocument or message. As mentioned in the enrollment process 900, thetransaction engine 205 stores a copy of the digital certificate of theuser, for example, in the mass storage 225. Thus, in step 1240 of theencryption process 1200, the transaction engine 205 requests the digitalcertificate of the user from the mass storage 225. In step 1245, themass storage 225 transmits the digital certificate corresponding to theuser, to the transaction engine 205. In step 1250, the transactionengine 205 transmits the digital certificate to the requestingapplication or vendor. According to one embodiment, the encryptionportion of the encryption process 1200 does not include theauthentication of a user. This is because the requesting vendor needsonly the public key of the user, and is not requesting any sensitivedata.

A skilled artisan will recognize from the disclosure herein that if aparticular user does not have a digital certificate, the trust engine110 may employ some or all of the enrollment process 900 in order togenerate a digital certificate for that particular user. Then, the trustengine 110 may initiate the encryption/decryption process 1200 andthereby provide the appropriate digital certificate. In addition, askilled artisan will recognize from the disclosure herein that steps1220 and 1235 through 1250 of the encryption/decryption process 1200 mayadvantageously employ some or all of the steps of the interoperabilityprocess of FIG. 9B, thereby providing interoperability between differingcryptographic systems that may, for example, need to process theencryption.

FIG. 13 illustrates a simplified block diagram of a trust engine system1300 according to aspects of yet another embodiment of the invention. Asshown in FIG. 13, the trust engine system 1300 comprises a plurality ofdistinct trust engines 1305, 1310, 1315, and 1320, respectively. Tofacilitate a more complete understanding of the invention, FIG. 13illustrates each trust engine, 1305, 1310, 1315, and 1320 as having atransaction engine, a depository, and an authentication engine. However,a skilled artisan will recognize that each transaction engine mayadvantageously comprise some, a combination, or all of the elements andcommunication channels disclosed with reference to FIGS. 1-8. Forexample, one embodiment may advantageously include trust engines havingone or more transaction engines, depositories, and cryptographic serversor any combinations thereof.

According to one embodiment of the invention, each of the trust engines1305, 1310, 1315 and 1320 are geographically separated, such that, forexample, the trust engine 1305 may reside in a first location, the trustengine 1310 may reside in a second location, the trust engine 1315 mayreside in a third location, and the trust engine 1320 may reside in afourth location. The foregoing geographic separation advantageouslydecreases system response time while increasing the security of theoverall trust engine system 1300.

For example, when a user logs onto the cryptographic system 100, theuser may be nearest the first location and may desire to beauthenticated. As described with reference to FIG. 10, to beauthenticated, the user provides current authentication data, such as abiometric or the like, and the current authentication data is comparedto that user's enrollment authentication data. Therefore, according toone example, the user advantageously provides current authenticationdata to the geographically nearest trust engine 1305. The transactionengine 1321 of the trust engine 1305 then forwards the currentauthentication data to the authentication engine 1322 also residing atthe first location. According to another embodiment, the transactionengine 1321 forwards the current authentication data to one or more ofthe authentication engines of the trust engines 1310, 1315, or 1320.

The transaction engine 1321 also requests the assembly of the enrollmentauthentication data from the depositories of, for example, each of thetrust engines, 1305 through 1320. According to this embodiment, eachdepository provides its portion of the enrollment authentication data tothe authentication engine 1322 of the trust engine 1305. Theauthentication engine 1322 then employs the encrypted data portionsfrom, for example, the first two depositories to respond, and assemblesthe enrollment authentication data into deciphered form. Theauthentication engine 1322 compares the enrollment authentication datawith the current authentication data and returns an authenticationresult to the transaction engine 1321 of the trust engine 1305.

Based on the above, the trust engine system 1300 employs the nearest oneof a plurality of geographically separated trust engines, 1305 through1320, to perform the authentication process. According to one embodimentof the invention, the routing of information to the nearest transactionengine may advantageously be performed at client-side applets executingon one or more of the user system 105, vendor system 120, or certificateauthority 115. According to an alternative embodiment, a moresophisticated decision process may be employed to select from the trustengines 1305 through 1320. For example, the decision may be based on theavailability, operability, speed of connections, load, performance,geographic proximity, or a combination thereof, of a given trust engine.

In this way, the trust engine system 1300 lowers its response time whilemaintaining the security advantages associated with geographicallyremote data storage facilities, such as those discussed with referenceto FIG. 7 where each data storage facility stores randomized portions ofsensitive data. For example, a security compromise at, for example, thedepository 1325 of the trust engine 1315 does not necessarily compromisethe sensitive data of the trust engine system 1300. This is because thedepository 1325 contains only non-decipherable randomized data that,without more, is entirely useless.

According to another embodiment, the trust engine system 1300 mayadvantageously include multiple cryptographic engines arranged similarto the authentication engines. The cryptographic engines mayadvantageously perform cryptographic functions such as those disclosedwith reference to FIGS. 1-8. According to yet another embodiment, thetrust engine system 1300 may advantageously replace the multipleauthentication engines with multiple cryptographic engines, therebyperforming cryptographic functions such as those disclosed withreference to FIGS. 1-8. According to yet another embodiment of theinvention, the trust engine system 1300 may replace each multipleauthentication engine with an engine having some or all of thefunctionality of the authentication engines, cryptographic engines, orboth, as disclosed in the foregoing.

Although the trust engine system 1300 is disclosed with reference to itspreferred and alternative embodiments, a skilled artisan will recognizethat the trust engine system 1300 may comprise portions of trust engines1305 through 1320. For example, the trust engine system 1300 may includeone or more transaction engines, one or more depositories, one or moreauthentication engines, or one or more cryptographic engines orcombinations thereof.

FIG. 14 illustrates a simplified block diagram of a trust engine System1400 according to aspects of yet another embodiment of the invention. Asshown in FIG. 14, the trust engine system 1400 includes multiple trustengines 1405, 1410, 1415 and 1420. According to one embodiment, each ofthe trust engines 1405, 1410, 1415 and 1420, comprise some or all of theelements of trust engine 110 disclosed with reference to FIGS. 1-8.According to this embodiment, when the client side applets of the usersystem 105, the vendor system 120, or the certificate authority 115,communicate with the trust engine system 1400, those communications aresent to the IP address of each of the trust engines 1405 through 1420.Further, each transaction engine of each of the trust engines, 1405,1410, 1415, and 1420, behaves similar to the transaction engine 1321 ofthe trust engine 1305 disclosed with reference to FIG. 13. For example,during an authentication process, each transaction engine of each of thetrust engines 1405, 1410, 1415, and 1420 transmits the currentauthentication data to their respective authentication engines andtransmits a request to assemble the randomized data stored in each ofthe depositories of each of the trust engines 1405 through 1420. FIG. 14does not illustrate all of these communications; as such illustrationwould become overly complex. Continuing with the authentication process,each of the depositories then communicates its portion of the randomizeddata to each of the authentication engines of the each of the trustengines 1405 through 1420. Each of the authentication engines of theeach of the trust engines employs its comparator to determine whetherthe current authentication data matches the enrollment authenticationdata provided by the depositories of each of the trust engines 1405through 1420. According to this embodiment, the result of the comparisonby each of the authentication engines is then transmitted to aredundancy module of the other three trust engines. For example, theresult of the authentication engine from the trust engine 1405 istransmitted to the redundancy modules of the trust engines 1410, 1415,and 1420. Thus, the redundancy module of the trust engine 1405 likewisereceives the result of the authentication engines from the trust engines1410, 1415, and 1420.

FIG. 15 illustrates a block diagram of the redundancy module of FIG. 14.The redundancy module comprises a comparator configured to receive theauthentication result from three authentication engines and transmitthat result to the transaction engine of the fourth trust engine. Thecomparator compares the authentication result form the threeauthentication engines, and if two of the results agree, the comparatorconcludes that the authentication result should match that of the twoagreeing authentication engines. This result is then transmitted back tothe transaction engine corresponding to the trust engine not associatedwith the three authentication engines.

Based on the foregoing, the redundancy module determines anauthentication result from data received from authentication enginesthat are preferably geographically remote from the trust engine of thatthe redundancy module. By providing such redundancy functionality, thetrust engine system 1400 ensures that a compromise of the authenticationengine of one of the trust engines 1405 through 1420, is insufficient tocompromise the authentication result of the redundancy module of thatparticular trust engine. A skilled artisan will recognize thatredundancy module functionality of the trust engine system 1400 may alsobe applied to the cryptographic engine of each of the trust engines 1405through 1420. However, such cryptographic engine communication was notshown in FIG. 14 to avoid complexity. Moreover, a skilled artisan willrecognize a wide number of alternative authentication result conflictresolution algorithms for the comparator of FIG. 15 are suitable for usein the present invention.

According to yet another embodiment of the invention, the trust enginesystem 1400 may advantageously employ the redundancy module duringcryptographic comparison steps. For example, some or all of theforegoing redundancy module disclosure with reference to FIGS. 14 and 15may advantageously be implemented during a hash comparison of documentsprovided by one or more parties during a particular transaction.

Although the foregoing invention has been described in terms of certainpreferred and alternative embodiments, other embodiments will beapparent to those of ordinary skill in the art from the disclosureherein. For example, the trust engine 110 may issue short-termcertificates, where the private cryptographic key is released to theuser for a predetermined period of time. For example, currentcertificate standards include a validity field that can be set to expireafter a predetermined amount of time. Thus, the trust engine 110 mayrelease a private key to a user where the private key would be validfor, for example, 24 hours. According to such an embodiment, the trustengine 110 may advantageously issue a new cryptographic key pair to beassociated with a particular user and then release the private key ofthe new cryptographic key pair. Then, once the private cryptographic keyis released, the trust engine 110 immediately expires any internal validuse of such private key, as it is no longer securable by the trustengine 110.

In addition, a skilled artisan will recognize that the cryptographicsystem 100 or the trust engine 110 may include the ability to recognizeany type of devices, such as, but not limited to, a laptop, a cellphone, a network, a biometric device or the like. According to oneembodiment, such recognition may come from data supplied in the requestfor a particular service, such as, a request for authentication leadingto access or use, a request for cryptographic functionality, or thelike. According to one embodiment, the foregoing request may include aunique device identifier, such as, for example, a processor ID.Alternatively, the request may include data in a particular recognizabledata format. For example, mobile and satellite phones often do notinclude the processing power for full X509.v3 heavy encryptioncertificates, and therefore do not request them. According to thisembodiment, the trust engine 110 may recognize the type of data formatpresented, and respond only in kind.

In an additional aspect of the system described above, context sensitiveauthentication can be provided using various techniques as will bedescribed below. Context sensitive authentication, for example as shownin FIG. 16, provides the possibility of evaluating not only the actualdata which is sent by the user when attempting to authenticate himself,but also the circumstances surrounding the generation and delivery ofthat data. Such techniques may also support transaction specific trustarbitrage between the user and trust engine 110 or between the vendorand trust engine 110, as will be described below.

As discussed above, authentication is the process of proving that a useris who he says he is. Generally, authentication requires demonstratingsome fact to an authentication authority. The trust engine 110 of thepresent invention represents the authority to which a user mustauthenticate himself. The user must demonstrate to the trust engine 110that he is who he says he is by either: knowing something that only theuser should know (knowledge-based authentication), having something thatonly the user should have (token-based authentication), or by beingsomething that only the user should be (biometric-based authentication).

Examples of knowledge-based authentication include without limitation apassword, PIN number, or lock combination. Examples of token-basedauthentication include without limitation a house key, a physical creditcard, a driver's license, or a particular phone number. Examples ofbiometric-based authentication include without limitation a fingerprint,handwriting analysis, facial scan, hand scan, ear scan, iris scan,vascular pattern, DNA, a voice analysis, or a retinal scan.

Each type of authentication has particular advantages and disadvantages,and each provides a different level of security. For example, it isgenerally harder to create a false fingerprint that matches someoneelse's than it is to overhear someone's password and repeat it. Eachtype of authentication also requires a different type of data to beknown to the authenticating authority in order to verify someone usingthat form of authentication.

As used herein, “authentication” will refer broadly to the overallprocess of verifying someone's identity to be who he says he is. An“authentication technique” will refer to a particular type ofauthentication based upon a particular piece of knowledge, physicaltoken, or biometric reading. “Authentication data” refers to informationwhich is sent to or otherwise demonstrated to an authenticationauthority in order to establish identity. “Enrollment data” will referto the data which is initially submitted to an authentication authorityin order to establish a baseline for comparison with authenticationdata. An “authentication instance” will refer to the data associatedwith an attempt to authenticate by an authentication technique.

The internal protocols and communications involved in the process ofauthenticating a user is described with reference to FIG. 10 above. Thepart of this process within which the context sensitive authenticationtakes place occurs within the comparison step shown as step 1045 of FIG.10. This step takes place within the authentication engine 215 andinvolves assembling the enrollment data 410 retrieved from thedepository 210 and comparing the authentication data provided by theuser to it. One particular embodiment of this process is shown in FIG.16 and described below.

The current authentication data provided by the user and the enrollmentdata retrieved from the depository 210 are received by theauthentication engine 215 in step 1600 of FIG. 16. Both of these sets ofdata may contain data which is related to separate techniques ofauthentication. The authentication engine 215 separates theauthentication data associated with each individual authenticationinstance in step 1605. This is necessary so that the authentication datais compared with the appropriate subset of the enrollment data for theuser (e.g. fingerprint authentication data should be compared withfingerprint enrollment data, rather than password enrollment data).

Generally, authenticating a user involves one or more individualauthentication instances, depending on which authentication techniquesare available to the user. These methods are limited by the enrollmentdata which were provided by the user during his enrollment process (ifthe user did not provide a retinal scan when enrolling, he will not beable to authenticate himself using a retinal scan), as well as the meanswhich may be currently available to the user (e.g. if the user does nothave a fingerprint reader at his current location, fingerprintauthentication will not be practical). In some cases, a singleauthentication instance may be sufficient to authenticate a user;however, in certain circumstances a combination of multipleauthentication instances may be used in order to more confidentlyauthenticate a user for a particular transaction.

Each authentication instance consists of data related to a particularauthentication technique (e.g. fingerprint, password, smart card, etc.)and the circumstances which surround the capture and delivery of thedata for that particular technique. For example, a particular instanceof attempting to authenticate via password will generate not only thedata related to the password itself, but also circumstantial data, knownas “metadata”, related to that password attempt. This circumstantialdata includes information such as: the time at which the particularauthentication instance took place, the network address from which theauthentication information was delivered, as well as any otherinformation as is known to those of skill in the art which may bedetermined about the origin of the authentication data (the type ofconnection, the processor serial number, etc.).

In many cases, only a small amount of circumstantial metadata will beavailable. For example, if the user is located on a network which usesproxies or network address translation or another technique which masksthe address of the originating computer, only the address of the proxyor router may be determined. Similarly, in many cases information suchas the processor serial number will not be available because of eitherlimitations of the hardware or operating system being used, disabling ofsuch features by the operator of the system, or other limitations of theconnection between the user's system and the trust engine 110.

As shown in FIG. 16, once the individual authentication instancesrepresented within the authentication data are extracted and separatedin step 1605, the authentication engine 215 evaluates each instance forits reliability in indicating that the user is who he claims to be. Thereliability for a single authentication instance will generally bedetermined based on several factors. These may be grouped as factorsrelating to the reliability associated with the authenticationtechnique, which are evaluated in step 1610, and factors relating to thereliability of the particular authentication data provided, which areevaluated in step 1815. The first group includes without limitation theinherent reliability of the authentication technique being used, and thereliability of the enrollment data being used with that method. Thesecond group includes without limitation the degree of match between theenrollment data and the data provided with the authentication instance,and the metadata associated with that authentication instance. Each ofthese factors may vary independently of the others.

The inherent reliability of an authentication technique is based on howhard it is for an imposter to provide someone else's correct data, aswell as the overall error rates for the authentication technique. Forpasswords and knowledge based authentication methods, this reliabilityis often fairly low because there is nothing that prevents someone fromrevealing their password to another person and for that second person touse that password. Even a more complex knowledge based system may haveonly moderate reliability since knowledge may be transferred from personto person fairly easily. Token based authentication, such as having aproper smart card or using a particular terminal to perform theauthentication, is similarly of low reliability used by itself, sincethere is no guarantee that the right person is in possession of theproper token.

However, biometric techniques are more inherently reliable because it isgenerally difficult to provide someone else with the ability to use yourfingerprints in a convenient manner, even intentionally. Becausesubverting biometric authentication techniques is more difficult, theinherent reliability of biometric methods is generally higher than thatof purely knowledge or token based authentication techniques. However,even biometric techniques may have some occasions in which a falseacceptance or false rejection is generated. These occurrences may bereflected by differing reliabilities for different implementations ofthe same biometric technique. For example, a fingerprint matching systemprovided by one company may provide a higher reliability than oneprovided by a different company because one uses higher quality opticsor a better scanning resolution or some other improvement which reducesthe occurrence of false acceptances or false rejections.

Note that this reliability may be expressed in different manners. Thereliability is desirably expressed in some metric which can be used bythe heuristics 530 and algorithms of the authentication engine 215 tocalculate the confidence level of each authentication. One preferredmode of expressing these reliabilities is as a percentage or fraction.For instance, fingerprints might be assigned an inherent reliability of97%, while passwords might only be assigned an inherent reliability of50%. Those of skill in the art will recognize that these particularvalues are merely exemplary and may vary between specificimplementations.

The second factor for which reliability must be assessed is thereliability of the enrollment. This is part of the “graded enrollment”process referred to above. This reliability factor reflects thereliability of the identification provided during the initial enrollmentprocess. For instance, if the individual initially enrolls in a mannerwhere they physically produce evidence of their identity to a notary orother public official, and enrollment data is recorded at that time andnotarized, the data will be more reliable than data which is providedover a network during enrollment and only vouched for by a digitalsignature or other information which is not truly tied to theindividual.

Other enrollment techniques with varying levels of reliability includewithout limitation: enrollment at a physical office of the trust engine110 operator; enrollment at a user's place of employment; enrollment ata post office or passport office; enrollment through an affiliated ortrusted party to the trust engine 110 operator; anonymous orpseudonymous enrollment in which the enrolled identity is not yetidentified with a particular real individual, as well as such othermeans as are known in the art.

These factors reflect the trust between the trust engine 110 and thesource of identification provided during the enrollment process. Forinstance, if enrollment is performed in association with an employerduring the initial process of providing evidence of identity, thisinformation may be considered extremely reliable for purposes within thecompany, but may be trusted to a lesser degree by a government agency,or by a competitor. Therefore, trust engines operated by each of theseother organizations may assign different levels of reliability to thisenrollment.

Similarly, additional data which is submitted across a network, butwhich is authenticated by other trusted data provided during a previousenrollment with the same trust engine 110 may be considered as reliableas the original enrollment data was, even though the latter data weresubmitted across an open network. In such circumstances, a subsequentnotarization will effectively increase the level of reliabilityassociated with the original enrollment data. In this way for example,an anonymous or pseudonymous enrollment may then be raised to a fullenrollment by demonstrating to some enrollment official the identity ofthe individual matching the enrolled data.

The reliability factors discussed above are generally values which maybe determined in advance of any particular authentication instance. Thisis because they are based upon the enrollment and the technique, ratherthan the actual authentication. In one embodiment, the step ofgenerating reliability based upon these factors involves looking uppreviously determined values for this particular authenticationtechnique and the enrollment data of the user. In a further aspect of anadvantageous embodiment of the present invention, such reliabilities maybe included with the enrollment data itself. In this way, these factorsare automatically delivered to the authentication engine 215 along withthe enrollment data sent from the depository 210.

While these factors may generally be determined in advance of anyindividual authentication instance, they still have an effect on eachauthentication instance which uses that particular technique ofauthentication for that user. Furthermore, although the values maychange over time (e.g. if the user re-enrolls in a more reliablefashion), they are not dependent on the authentication data itself. Bycontrast, the reliability factors associated with a single specificinstance's data may vary on each occasion. These factors, as discussedbelow, must be evaluated for each new authentication in order togenerate reliability scores in step 1815.

The reliability of the authentication data reflects the match betweenthe data provided by the user in a particular authentication instanceand the data provided during the authentication enrollment. This is thefundamental question of whether the authentication data matches theenrollment data for the individual the user is claiming to be. Normally,when the data do not match, the user is considered to not besuccessfully authenticated, and the authentication fails. The manner inwhich this is evaluated may change depending on the authenticationtechnique used. The comparison of such data is performed by thecomparator 515 function of the authentication engine 215 as shown inFIG. 5.

For instance, matches of passwords are generally evaluated in a binaryfashion. In other words, a password is either a perfect match, or afailed match. It is usually not desirable to accept as even a partialmatch a password which is close to the correct password if it is notexactly correct. Therefore, when evaluating a password authentication,the reliability of the authentication returned by the comparator 515 istypically either 100% (correct) or 0% (wrong), with no possibility ofintermediate values.

Similar rules to those for passwords are generally applied to tokenbased authentication methods, such as smart cards. This is becausehaving a smart card which has a similar identifier or which is similarto the correct one, is still just as wrong as having any other incorrecttoken. Therefore tokens tend also to be binary authenticators: a usereither has the right token, or he doesn't.

However, certain types of authentication data, such as questionnairesand biometrics, are generally not binary authenticators. For example, afingerprint may match a reference fingerprint to varying degrees. Tosome extent, this may be due to variations in the quality of the datacaptured either during the initial enrollment or in subsequentauthentications. (A fingerprint may be smudged or a person may have astill healing scar or burn on a particular finger.) In other instancesthe data may match less than perfectly because the information itself issomewhat variable and based upon pattern matching. (A voice analysis mayseem close but not quite right because of background noise, or theacoustics of the environment in which the voice is recorded, or becausethe person has a cold.) Finally, in situations where large amounts ofdata are being compared, it may simply be the case that much of the datamatches well, but some doesn't. (A ten-question questionnaire may haveresulted in eight correct answers to personal questions, but twoincorrect answers.) For any of these reasons, the match between theenrollment data and the data for a particular authentication instancemay be desirably assigned a partial match value by the comparator 515.In this way, the fingerprint might be said to be a 85% match, the voiceprint a 65% match, and the questionnaire an 80% match, for example.

This measure (degree of match) produced by the comparator 515 is thefactor representing the basic issue of whether an authentication iscorrect or not. However, as discussed above, this is only one of thefactors which may be used in determining the reliability of a givenauthentication instance. Note also that even though a match to somepartial degree may be determined, that ultimately, it may be desirableto provide a binary result based upon a partial match. In an alternatemode of operation, it is also possible to treat partial matches asbinary, i.e. either perfect (100%) or failed (0%) matches, based uponwhether or not the degree of match passes a particular threshold levelof match. Such a process may be used to provide a simple pass/fail levelof matching for systems which would otherwise produce partial matches.

Another factor to be considered in evaluating the reliability of a givenauthentication instance concerns the circumstances under which theauthentication data for this particular instance are provided. Asdiscussed above, the circumstances refer to the metadata associated witha particular authentication instance. This may include withoutlimitation such information as: the network address of theauthenticator, to the extent that it can be determined; the time of theauthentication; the mode of transmission of the authentication data(phone line, cellular, network, etc.); and the serial number of thesystem of the authenticator.

These factors can be used to produce a profile of the type ofauthentication that is normally requested by the user. Then, thisinformation can be used to assess reliability in at least two manners.One manner is to consider whether the user is requesting authenticationin a manner which is consistent with the normal profile ofauthentication by this user. If the user normally makes authenticationrequests from one network address during business days (when she is atwork) and from a different network address during evenings or weekends(when she is at home), an authentication which occurs from the homeaddress during the business day is less reliable because it is outsidethe normal authentication profile. Similarly, if the user normallyauthenticates using a fingerprint biometric and in the evenings, anauthentication which originates during the day using only a password isless reliable.

An additional way in which the circumstantial metadata can be used toevaluate the reliability of an instance of authentication is todetermine how much corroboration the circumstance provides that theauthenticator is the individual he claims to be. For instance, if theauthentication comes from a system with a serial number known to beassociated with the user, this is a good circumstantial indicator thatthe user is who they claim to be. Conversely, if the authentication iscoming from a network address which is known to be in Los Angeles whenthe user is known to reside in London, this is an indication that thisauthentication is less reliable based on its circumstances.

It is also possible that a cookie or other electronic data may be placedupon the system being used by a user when they interact with a vendorsystem or with the trust engine 110. This data is written to the storageof the system of the user and may contain an identification which may beread by a Web browser or other software on the user system. If this datais allowed to reside on the user system between sessions (a “persistentcookie”), it may be sent with the authentication data as furtherevidence of the past use of this system during authentication of aparticular user. In effect, the metadata of a given instance,particularly a persistent cookie, may form a sort of token basedauthenticator itself.

Once the appropriate reliability factors based on the technique and dataof the authentication instance are generated as described above in steps1610 and 1615 respectively, they are used to produce an overallreliability for the authentication instance provided in step 1620. Onemeans of doing this is simply to express each reliability as apercentage and then to multiply them together.

For example, suppose the authentication data is being sent in from anetwork address known to be the user's home computer completely inaccordance with the user's past authentication profile (100%), and thetechnique being used is fingerprint identification (97%), and theinitial finger print data was roistered through the user's employer withthe trust engine 110 (90%), and the match between the authenticationdata and the original fingerprint template in the enrollment data isvery good (99%). The overall reliability of this authentication instancecould then be calculated as the product of these reliabilities:100%*97%*90%*99%−86.4% reliability.

This calculated reliability represents the reliability of one singleinstance of authentication. The overall reliability of a singleauthentication instance may also be calculated using techniques whichtreat the different reliability factors differently, for example byusing formulas where different weights are assigned to each reliabilityfactor. Furthermore, those of skill in the art will recognize that theactual values used may represent values other than percentages and mayuse non-arithmetic systems. One embodiment may include a module used byan authentication requestor to set the weights for each factor and thealgorithms used in establishing the overall reliability of theauthentication instance.

The authentication engine 215 may use the above techniques andvariations thereof to determine the reliability of a singleauthentication instance, indicated as step 1620. However, it may beuseful in many authentication situations for multiple authenticationinstances to be provided at the same time. For example, while attemptingto authenticate himself using the system of the present invention, auser may provide a user identification, fingerprint authentication data,a smart card, and a password. In such a case, three independentauthentication instances are being provided to the trust engine 110 forevaluation. Proceeding to step 1625, if the authentication engine 215determines that the data provided by the user includes more than oneauthentication instance, then each instance in turn will be selected asshown in step 1630 and evaluated as described above in steps 1610, 1615and 1620.

Note that many of the reliability factors discussed may vary from one ofthese instances to another. For instance, the inherent reliability ofthese techniques is likely to be different, as well as the degree ofmatch provided between the authentication data and the enrollment data.Furthermore, the user may have provided enrollment data at differenttimes and under different circumstances for each of these techniques,providing different enrollment reliabilities for each of these instancesas well. Finally, even though the circumstances under which the data foreach of these instances is being submitted is the same, the use of suchtechniques may each fit the profile of the user differently, and so maybe assigned different circumstantial reliabilities. (For example, theuser may normally use their password and fingerprint, but not theirsmart card.)

As a result, the final reliability for each of these authenticationinstances may be different from One another. However, by using multipleinstances together, the overall confidence level for the authenticationwill tend to increase.

Once the authentication engine has performed steps 1610 through 1620 forall of the authentication instances provided in the authentication data,the reliability of each instance is used in step 1635 to evaluate theoverall authentication confidence level. This process of combining theindividual authentication instance reliabilities into the authenticationconfidence level may be modeled by various methods relating theindividual reliabilities produced, and may also address the particularinteraction between some of these authentication techniques. (Forexample, multiple knowledge-based systems such as passwords may produceless confidence than a single password and even a fairly weak biometric,such as a basic voice analysis.)

One means in which the authentication engine 215 may combine thereliabilities of multiple concurrent authentication instances togenerate a final confidence level is to multiply the unreliability ofeach instance to arrive at a total unreliability. The unreliability isgenerally the complementary percentage of the reliability. For example,a technique which is 84% reliable is 16% unreliable. The threeauthentication instances described above (fingerprint, smart card,password) which produce reliabilities of 86%, 75%, and 72% would havecorresponding unreliabilities of (100−86)%, (100−75)% and (100−72)%, or14%, 25%, and 28%, respectively. By multiplying these unreliabilities,we get a cumulative unreliability of 14%*25%*28%-0.98% unreliability,which corresponds to a reliability of 99.02%.

In an additional mode of operation, additional factors and heuristics530 may be applied within the authentication engine 215 to account forthe interdependence of various authentication techniques. For example,if someone has unauthorized access to a particular home computer, theyprobably have access to the phone line at that address as well.Therefore, authenticating based on an originating phone number as wellas upon the serial number of the authenticating system does not add muchto the overall confidence in the authentication. However, knowledgebased authentication is largely independent of token basedauthentication (i.e. if someone steals your cellular phone or keys, theyare no more likely to know your PIN or password than if they hadn't).

Furthermore, different vendors or other authentication requestors maywish to weigh different aspects of the authentication differently. Thismay include the use of separate weighing factors or algorithms used incalculating the reliability of individual instances as well as the useof different means to evaluate authentication events with multipleinstances.

For instance, vendors for certain types of transactions, for instancecorporate email systems, may desire to authenticate primarily based uponheuristics and other circumstantial data by default. Therefore, they mayapply high weights to factors related to the metadata and other profilerelated information associated with the circumstances surroundingauthentication events. This arrangement could be used to ease the burdenon users during normal operating hours, by not requiring more from theuser than that he be logged on to the correct machine during businesshours. However, another vendor may weigh authentications coming from aparticular technique most heavily, for instance fingerprint matching,because of a policy decision that such a technique is most suited toauthentication for the particular vendor's purposes.

Such varying weights may be defined by the authentication requestor ingenerating the authentication request and sent to the trust engine 110with the authentication request in one mode of operation. Such optionscould also be set as preferences during an initial enrollment processfor the authentication requestor and stored within the authenticationengine in another mode of operation.

Once the authentication engine 215 produces an authentication confidencelevel for the authentication data provided, this confidence level isused to complete the authentication request in step 1640, and thisinformation is forwarded from the authentication engine 215 to thetransaction engine 205 for inclusion in a message to the authenticationrequestor.

The process described above is merely exemplary, and those of skill inthe art will recognize that the steps need not be performed in the ordershown or that only certain of the steps are desired to be performed, orthat a variety of combinations of steps may be desired. Furthermore,certain steps, such as the evaluation of the reliability of eachauthentication instance provided, may be carried out in parallel withone another if circumstances permit.

In a further aspect of this invention, a method is provided toaccommodate conditions when the authentication confidence level producedby the process described above fails to meet the required trust level ofthe vendor or other party requiring the authentication. In circumstancessuch as these where a gap exists between the level of confidenceprovided and the level of trust desired, the operator of the trustengine 110 is in a position to provide opportunities for one or bothparties to provide alternate data or requirements in order to close thistrust gap. This process will be referred to as “trust arbitrage” herein.

Trust arbitrage may take place within a framework of cryptographicauthentication as described above with reference to FIGS. 10 and 11. Asshown therein, a vendor or other party will request authentication of aparticular user in association with a particular transaction. In onecircumstance, the vendor simply requests an authentication, eitherpositive or negative, and after receiving appropriate data from theuser, the trust engine 110 will provide such a binary authentication. Incircumstances such as these, the degree of confidence required in orderto secure a positive authentication is determined based upon preferencesset within the trust engine 110.

However, it is also possible that the vendor may request a particularlevel of trust in order to complete a particular transaction. Thisrequired level may be included with the authentication request (e.g.authenticate this user to 98% confidence) or may be determined by thetrust engine 110 based on other factors associated with the transaction(i.e. authenticate this user as appropriate for this transaction). Onesuch factor might be the economic value of the transaction. Fortransactions which have greater economic value, a higher degree of trustmay be required. Similarly, for transactions with high degrees of risk ahigh degree of trust may be required. Conversely, for transactions whichare either of low risk or of low value, lower trust levels may berequired by the vendor or other authentication requestor.

The process of trust arbitrage occurs between the steps of the trustengine 110 receiving the authentication data in step 1050 of FIG. 10 andthe return of an authentication result to the vendor in step 1055 ofFIG. 10. Between these steps, the process which leads to the evaluationof trust levels and the potential trust arbitrage occurs as shown inFIG. 17. In circumstances where simple binary authentication isperformed, the process shown in FIG. 17 reduces to having thetransaction engine 205 directly compare the authentication data providedwith the enrollment data for the identified user as discussed above withreference to FIG. 10, flagging any difference as a negativeauthentication.

As shown in FIG. 17, the first step after receiving the data in step1050 is for the transaction engine 205 to determine the trust levelwhich is required for a positive authentication for this particulartransaction in step 1710. This step may be performed by one of severaldifferent methods. The required trust level may be specified to thetrust engine 110 by the authentication requestor at the time when theauthentication request is made. The authentication requestor may alsoset a preference in advance which is stored within the depository 210 orother storage which is accessible by the transaction engine 205. Thispreference may then be read and used each time an authentication requestis made by this authentication requestor. The preference may also beassociated with a particular user as a security measure such that aparticular level of trust is always required in order to authenticatethat user, the user preference being stored in the depository 210 orother storage media accessible by the transaction engine 205. Therequired level may also be derived by the transaction engine 205 orauthentication engine 215 based upon information provided in theauthentication request, such as the value and risk level of thetransaction to be authenticated.

In one mode of operation, a policy management module or other softwarewhich is used when generating the authentication request is used tospecify the required degree of trust for the authentication of thetransaction. This may be used to provide a series of rules to followwhen assigning the required level of trust based upon the policies whichare specified within the policy management module. One advantageous modeof operation is for such a module to be incorporated with the web serverof a vendor in order to appropriately determine required level of trustfor transactions initiated with the vendor's web server. In this way,transaction requests from users may be assigned a required trust levelin accordance with the policies of the vendor and such information maybe forwarded to the trust engine 110 along with the authenticationrequest.

This required trust level correlates with the degree of certainty thatthe vendor wants to have that the individual authenticating is in factwho he identifies himself as. For example, if the transaction is onewhere the vendor wants a fair degree of certainty because goods arechanging hands, the vendor may require a trust level of 85%. Forsituation where the vendor is merely authenticating the user to allowhim to view members only content or exercise privileges on a chat room,the downside risk may be small enough that the vendor requires only a60% trust level. However, to enter into a production contract with avalue of tens of thousands of dollars, the vendor may require a trustlevel of 99% or more.

This required trust level represents a metric to which the user mustauthenticate himself in order to complete the transaction. If therequired trust level is 85% for example, the user must provideauthentication to the trust engine 110 sufficient for the trust engine110 to say with 85% confidence that the user is who they say they are.It is the balance between this required trust level and theauthentication confidence level which produces either a positiveauthentication (to the satisfaction of the vendor) or a possibility oftrust arbitrage.

As shown in FIG. 17, after the transaction engine 205 receives therequired trust level, it compares in step 1720 the required trust levelto the authentication confidence level which the authentication engine215 calculated for the current authentication (as discussed withreference to FIG. 16). If the authentication confidence level is higherthan the required trust level for the transaction in step 1730, then theprocess moves to step 1740 where a positive authentication for thistransaction is produced by the transaction engine 205. A message to thiseffect will then be inserted into the authentication results andreturned to the vendor by the transaction engine 205 as shown in step1055 (see FIG. 10).

However, if the authentication confidence level does not fulfill therequired trust level in step 1730, then a confidence gap exists for thecurrent authentication, and trust arbitrage is conducted in step 1750.Trust arbitrage is described more completely with reference to FIG. 18below. This process as described below takes place within thetransaction engine 205 of the trust engine 110. Because noauthentication or other cryptographic operations are needed to executetrust arbitrage (other than those required for the SSL communicationbetween the transaction engine 205 and other components), the processmay be performed outside the authentication engine 215. However, as willbe discussed below, any reevaluation of authentication data or othercryptographic or authentication events will require the transactionengine 205 to resubmit the appropriate data to the authentication engine215. Those of skill in the art will recognize that the trust arbitrageprocess could alternately be structured to take place partially orentirely within the authentication engine 215 itself.

As mentioned above, trust arbitrage is a process where the trust engine110 mediates a negotiation between the vendor and user in an attempt tosecure a positive authentication where appropriate. As shown in step1805, the transaction engine 205 first determines whether or not thecurrent situation is appropriate for trust arbitrage. This may bedetermined based upon the circumstances of the authentication, e.g.whether this authentication has already been through multiple cycles ofarbitrage, as well as upon the preferences of either the vendor or user,as will be discussed further below.

In such circumstances where arbitrage is not possible, the processproceeds to step 1810 where the transaction engine 205 generates anegative authentication and then inserts it into the authenticationresults which are sent to the vendor in step 1055 (see FIG. 10). Onelimit which may be advantageously used to prevent authentications frompending indefinitely is to set a time-out period from the initialauthentication request. In this way, any transaction which is notpositively authenticated within the time limit is denied furtherarbitrage and negatively authenticated. Those of skill in the art willrecognize that such a time limit may vary depending upon thecircumstances of the transaction and the desires of the user and vendor.Limitations may also be placed upon the number of attempts that may bemade at providing a successful authentication. Such limitations may behandled by an attempt limiter 535 as shown in FIG. 5.

If arbitrage is not prohibited in step 1805, the transaction engine 205will then engage in negotiation with one or both of the transactingparties. The transaction engine 205 may send a message to the userrequesting some form of additional authentication in order to boost theauthentication confidence level produced as shown in step 1820. In thesimplest form, this may simply indicates that authentication wasinsufficient. A request to produce one or more additional authenticationinstances to improve the overall confidence level of the authenticationmay also be sent.

If the user provides some additional authentication instances in step1825, then the transaction engine 205 adds these authenticationinstances to the authentication data for the transaction and forwards itto the authentication engine 215 as shown in step 1015 (see FIG. 10),and the authentication is reevaluated based upon both the pre-existingauthentication instances for this transaction and the newly providedauthentication instances.

An additional type of authentication may be a request from the trustengine 110 to make some form of person-to-person contact between thetrust engine 110 operator (or a trusted associate) and the user, forexample, by phone call. This phone call or other non-computerauthentication can be used to provide personal contact with theindividual and also to conduct some form of questionnaire basedauthentication. This also may give the opportunity to verify anoriginating telephone number and potentially a voice analysis of theuser when he calls in. Even if no additional authentication data can beprovided, the additional context associated with the user's phone numbermay improve the reliability of the authentication context. Any reviseddata or circumstances based upon this phone call are fed into the trustengine 110 for use in consideration of the authentication request.

Additionally, in step 1820 the trust engine 110 may provide anopportunity for the user to purchase insurance, effectively buying amore confident authentication. The operator of the trust engine 110 may,at times, only want to make such an option available if the confidencelevel of the authentication is above a certain threshold to begin with.In effect, this user side insurance is a way for the trust engine 110 tovouch for the user when the authentication meets the normal requiredtrust level of the trust engine 110 for authentication, but does notmeet the required trust level of the vendor for this transaction. Inthis way, the user may still successfully authenticate to a very highlevel as may be required by the vendor, even though he only hasauthentication instances which produce confidence sufficient for thetrust engine 110.

This function of the trust engine 110 allows the trust engine 110 tovouch for someone who is authenticated to the satisfaction of the trustengine 110, but not of the vendor. This is analogous to the functionperformed by a notary in adding his signature to a document in order toindicate to someone reading the document at a later time that the personwhose signature appears on the document is in fact the person who signedit. The signature of the notary testifies to the act of signing by theuser. In the same way, the trust engine is providing an indication thatthe person transacting is who they say they are.

However, because the trust engine 110 is artificially boosting the levelof confidence provided by the user, there is a greater risk to the trustengine 110 operator, since the user is not actually meeting the requiredtrust level of the vendor. The cost of the insurance is designed tooffset the risk of a false positive authentication to the trust engine110 (who may be effectively notarizing the authentications of the user).The user pays the trust engine 110 operator to take the risk ofauthenticating to a higher level of confidence than has actually beenprovided.

Because such an insurance system allows someone to effectively buy ahigher confidence rating from the trust engine 110, both vendors andusers may wish to prevent the use of user side insurance in certaintransactions. Vendors may wish to limit positive authentications tocircumstances where they know that actual authentication data supportsthe degree of confidence which they require and so may indicate to thetrust engine 110 that user side insurance is not to be allowed.Similarly, to protect his online identity, a user may wish to preventthe use of user side insurance on his account, or may wish to limit itsuse to situations where the authentication confidence level without theinsurance is higher than a certain limit. This may be used as a securitymeasure to prevent someone from overhearing a password or stealing asmart card and using them to falsely authenticate to a low level ofconfidence, and then purchasing insurance to produce a very high levelof (false) confidence. These factors may be evaluated in determiningwhether user side insurance is allowed.

If user purchases insurance in step 1840, then the authenticationconfidence level is adjusted based upon the insurance purchased in step1845, and the authentication confidence level and required trust levelare again compared in step 1730 (see FIG. 17). The process continuesfrom there, and may lead to either a positive authentication in step1740 (see FIG. 17), or back into the trust arbitrage process in step1750 for either further arbitrage (if allowed) or a negativeauthentication in step 1810 if further arbitrage is prohibited.

In addition to sending a message to the user in step 1820, thetransaction engine 205 may also send a message to the vendor in step1830 which indicates that a pending authentication is currently belowthe required trust level. The message may also offer various options onhow to proceed to the vendor. One of these Options is to simply informthe vendor of what the current authentication confidence level is andask if the vendor wishes to maintain their current unfulfilled requiredtrust level. This may be beneficial because in some cases, the vendormay have independent means for authenticating the transaction or mayhave been using a default set of requirements which generally result ina higher required level being initially specified than is actuallyneeded for the particular transaction at hand.

For instance, it may be standard practice that all incoming purchaseorder transactions with the vendor are expected to meet a 98% trustlevel. However, if an order was recently discussed by phone between thevendor and a long-standing customer, and immediately thereafter thetransaction is authenticated, but only to a 93% confidence level, thevendor may wish to simply lower the acceptance threshold for thistransaction, because the phone call effectively provides additionalauthentication to the vendor. In certain circumstances, the vendor maybe willing to lower their required trust level, but not all the way tothe level of the current authentication confidence. For instance, thevendor in the above example might consider that the phone call prior tothe order might merit a 4% reduction in the degree of trust needed;however, this is still greater than the 93% confidence produced by theuser.

If the vendor does adjust their required trust level in step 1835, thenthe authentication confidence level produced by the authentication andthe required trust level are compared in step 1730 (see FIG. 17). If theconfidence level now exceeds the required trust level, a positiveauthentication may be generated in the transaction engine 205 in step1740 (see FIG. 17). If not, further arbitrage may be attempted asdiscussed above if it is permitted.

In addition to requesting an adjustment to the required trust level, thetransaction engine 205 may also offer vendor side insurance to thevendor requesting the authentication. This insurance serves a similarpurpose to that described above for the user side insurance. Here,however, rather than the cost corresponding to the risk being taken bythe trust engine 110 in authenticating above the actual authenticationconfidence level produced, the cost of the insurance corresponds to therisk being taken by the vendor in accepting a lower trust level in theauthentication.

Instead of just lowering their actual required trust level, the vendorhas the option of purchasing insurance to protect itself from theadditional risk associated with a lower level of trust in theauthentication of the user. As described above, it may be advantageousfor the vendor to only consider purchasing such insurance to cover thetrust gap in conditions where the existing authentication is alreadyabove a certain threshold.

The availability of such vendor side insurance allows the vendor theoption to either: lower his trust requirement directly at no additionalcost to himself, bearing the risk of a false authentication himself(based on the lower trust level required); or, buying insurance for thetrust gap between the authentication confidence level and hisrequirement, with the trust engine 110 operator bearing the risk of thelower confidence level which has been provided. By purchasing theinsurance, the vendor effectively keeps his high trust levelrequirement; because the risk of a false authentication is shifted tothe trust engine 110 operator.

If the vendor purchases insurance in step 1840, the authenticationconfidence level and required trust levels are compared in step 1730(see FIG. 17), and the process continues as described above.

Note that it is also possible that both the user and the vendor respondto messages from the trust engine 110. Those of skill in the art willrecognize that there are multiple ways in which such situations can behandled. One advantageous mode of handling the possibility of multipleresponses is simply to treat the responses in a first-come, first-servedmanner. For example, if the vendor responds with a lowered requiredtrust level and immediately thereafter the user also purchases insuranceto raise his authentication level, the authentication is firstreevaluated based upon the lowered trust requirement from the vendor. Ifthe authentication is now positive, the user's insurance purchase isignored. In another advantageous mode of operation, the user might onlybe charged for the level of insurance required to meet the new, loweredtrust requirement of the vendor (if a trust gap remained even with thelowered vendor trust requirement).

If no response from either party is received during the trust arbitrageprocess at step 1850 within the time limit set for the authentication,the arbitrage is reevaluated in step 1805. This effectively begins thearbitrage process again. If the time limit was final or othercircumstances prevent further arbitrage in step 1805, a negativeauthentication is generated by the transaction engine 205 in step 1810and returned to the vendor in step 1055 (see FIG. 10). If not, newmessages may be sent to the user and vendor, and the process may berepeated as desired.

Note that for certain types of transactions, for instance, digitallysigning documents which are not part of a transaction, there may notnecessarily be a vendor or other third party; therefore the transactionis primarily between the user and the trust engine 110. In circumstancessuch as these, the trust engine 110 will have its own required trustlevel which must be satisfied in order to generate a positiveauthentication. However, in such circumstances, it will often not bedesirable for the trust engine 110 to offer insurance to the user inorder for him to raise the confidence of his own signature.

The process described above and shown in FIGS. 16-18 may be carried outusing various communications modes as described above with reference tothe trust engine 110. For instance, the messages may be web-based andsent using SSL connections between the trust engine 110 and appletsdownloaded in real time to browsers running on the user or vendorsystems. In an alternate mode of operation, certain dedicatedapplications may be in use by the user and vendor which facilitate sucharbitrage and insurance transactions. In another alternate mode ofoperation, secure email operations may be used to mediate the arbitragedescribed above, thereby allowing deferred evaluations and batchprocessing of authentications. Those of skill in the art will recognizethat different communications modes may be used as are appropriate forthe circumstances and authentication requirements of the vendor.

The following description with reference to FIG. 19 describes a sampletransaction which integrates the various aspects of the presentinvention as described above. This example illustrates the overallprocess between a user and a vendor as mediates by the trust engine 110.Although the various steps and components as described in detail abovemay be used to carry out the following transaction, the processillustrated focuses on the interaction between the trust engine 110,user and vendor.

The transaction begins when the user, while viewing web pages online,fills out an order form on the web site of the vendor in step 1900. Theuser wishes to submit this order form to the vendor, signed with hisdigital signature. In order to do this, the user submits the order formwith his request for a signature to the trust engine 110 in step 1905.The user will also provide authentication data which will be used asdescribed above to authenticate his identity.

In step 1910 the authentication data is compared to the enrollment databy the trust engine 110 as discussed above, and if a positiveauthentication is produced, the hash of the order form, signed with theprivate key of the user, is forwarded to the vendor along with the orderform itself.

The vendor receives the signed form in step 1915, and then the vendorwill generate an invoice or other contract related to the purchase to bemade in step 1920. This contract is sent back to the user with a requestfor a signature in step 1925. The vendor also sends an authenticationrequest for this contract transaction to the trust engine 110 in step1930 including a hash of the contract which will be signed by bothparties. To allow the contract to be digitally signed by both parties,the vendor also includes authentication data for itself so that thevendor's signature upon the contract can later be verified if necessary.

As discussed above, the trust engine 110 then verifies theauthentication data provided by the vendor to confirm the vendor'sidentity, and if the data produces a positive authentication in step1935, continues with step 1955 when the data is received from the user.If the vendor's authentication data does not match the enrollment dataof the vendor to the desired degree, a message is returned to the vendorrequesting further authentication. Trust arbitrage may be performed hereif necessary, as described above, in order for the vendor tosuccessfully authenticate itself to the trust engine 110.

When the user receives the contract in step 1940, he reviews it,generates authentication data to sign it if it is acceptable in step1945, and then sends a hash of the contract and his authentication datato the trust engine 110 in step 1950. The trust engine 110 verifies theauthentication data in step 1955 and if the authentication is good,proceeds to process the contract as described below. As discussed abovewith reference to FIGS. 17 and 18, trust arbitrage may be performed asappropriate to close any trust gap which exists between theauthentication confidence level and the required authentication levelfor the transaction.

The trust engine 110 signs the hash of the contract with the user'sprivate key, and sends this signed hash to the vendor in step 1960,signing the complete message on its own behalf, i.e., including a hashof the complete message (including the user's signature) encrypted withthe private key 510 of the trust engine 110. This message is received bythe vendor in step 1965. The message represents a signed contract (hashof contract encrypted using user's private key) and a receipt from thetrust engine 110 (the hash of the message including the signed contract,encrypted using the trust engine 110's private key).

The trust engine 110 similarly prepares a hash of the contract with thevendor's private key in step 1970, and forwards this to the user, signedby the trust engine 110. In this way, the user also receives a copy ofthe contract, signed by the vendor, as well as a receipt, signed by thetrust engine 110, for delivery of the signed contract in step 1975.

In addition to the foregoing, an additional aspect of the inventionprovides a cryptographic Service Provider Module (SPM) which may beavailable to a client side application as a means to access functionsprovided by the trust engine 110 described above. One advantageous wayto provide such a service is for the cryptographic SPM is to mediatecommunications between a third party Application Programming Interface(API) and a trust engine 110 which is accessible via a network or otherremote connection. A sample cryptographic SPM is described below withreference to FIG. 20.

For example, on a typical system, a number of API's are available toprogrammers. Each API provides a set of function calls which may be madeby an application 2000 running upon the system. Examples of API's whichprovide programming interfaces suitable for cryptographic functions,authentication functions, and other security function include theCryptographic API (CAPI) 2010 provided by Microsoft with its Windowsoperating systems, and the Common Data Security Architecture (CDSA),sponsored by IBM, Intel and other members of the Open Group. CAPI willbe used as an exemplary security API in the discussion that follows.However, the cryptographic SPM described could be used with CDSA orother security API's as are known in the art.

This API is used by a user system 105 or vendor system 120 when a callis made for a cryptographic function. Included among these functions maybe requests associated with performing various cryptographic operations,such as encrypting a document with a particular key, signing a document,requesting a digital certificate, verifying a signature upon a signeddocument, and such other cryptographic functions as are described hereinor known to those of skill in the art.

Such cryptographic functions are normally performed locally to thesystem upon which CAPI 2010 is located. This is because generally thefunctions called require the use of either resources of the local usersystem 105, such as a fingerprint reader, or software functions whichare programmed using libraries which are executed on the local machine.Access to these local resources is normally provided by one or moreService Provider Modules (SPM's) 2015, 2020 as referred to above whichprovide resources with which the cryptographic functions are carriedout. Such SPM's may include software libraries 2015 to performencrypting or decrypting operations, or drivers and applications 2020which are capable of accessing specialized hardware 2025, such asbiometric scanning devices. In much the way that CAPI 2010 providesfunctions which may be used by an application 2000 of the system 105,the SPM's 2015, 2020 provide CAPI with access to the lower levelfunctions and resources associated with the available services upon thesystem.

In accordance with the invention, it is possible to provide acryptographic SPM 2030 which is capable of accessing the cryptographicfunctions provided by the trust engine 110 and making these functionsavailable to an application 2000 through CAPI 2010. Unlike embodimentswhere CAPI 2010 is only able to access resources which are locallyavailable through SPM's 2015, 2020, a cryptographic SPM 2030 asdescribed herein would be able to submit requests for cryptographicoperations to a remotely-located, network-accessible trust engine 110 inorder to perform the operations desired.

For instance, if an application 2000 has a need for a cryptographicoperation, such as signing a document, the application 2000 makes afunction call to the appropriate CAPI 2010 function. CAPI 2010 in turnwill execute this function, making use of the resources which are madeavailable to it by the SPM's 2015, 2020 and the cryptographic SPM 2030.In the case of a digital signature function, the cryptographic SPM 2030will generate an appropriate request which will be sent to the trustengine 110 across the communication link 125.

The operations which occur between the cryptographic SPM 2030 and thetrust engine 110 are the same operations that would be possible betweenany other system and the trust engine 110. However, these functions areeffectively made available to a user system 105 through CAPI 2010 suchthat they appear to be locally available upon the user system 105itself. However, unlike ordinary SPM's 2015, 2020, the functions arebeing carried out on the remote trust engine 110 and the results relayedto the cryptographic SPM 2030 in response to appropriate requests acrossthe communication link 125.

This cryptographic SPM 2030 makes a number of operations available tothe user system 105 or a vendor system 120 which might not otherwise beavailable. These functions include without limitation: encryption anddecryption of documents; issuance of digital certificates; digitalsigning of documents; verification of digital signatures; and such otheroperations as will be apparent to those of skill in the art.

In a separate embodiment, the present invention comprises a completesystem for performing the data securing methods of the present inventionon any data set. The computer system of this embodiment comprises a datasplitting module that comprises the functionality shown in FIG. 8 anddescribed herein. In one embodiment of the present invention, the datasplitting module, sometimes referred to herein as a secure data parser,comprises a parser program or software suite which comprises datasplitting, encryption and decryption, reconstitution or reassemblyfunctionality. This embodiment may further comprise a data storagefacility or multiple data storage facilities, as well. The datasplitting module, or secure data parser, comprises a cross-platformsoftware module suite which integrates within an electronicinfrastructure, or as an add-on to any application which requires theultimate security of its data elements. This parsing process operates onany type of data set, and on any and all file types, or in a database onany row, column or cell of data in that database.

The parsing process of the present invention may, in one embodiment, bedesigned in a modular tiered fashion, and any encryption process issuitable for use in the process of the present invention. The modulartiers of the parsing and splitting process of the present invention mayinclude, but are not limited to, 1) cryptographic split, dispersed andsecurely stored in multiple locations; 2) encrypt, cryptographicallysplit, dispersed and securely stored in multiple locations; 3) encrypt,cryptographically split, encrypt each share, then dispersed and securelystored in multiple locations; and 4) encrypt, cryptographically split,encrypt each share with a different type of encryption than was used inthe first step, then dispersed and securely stored in multiplelocations.

The process comprises, in one embodiment, splitting of the dataaccording to the contents of a generated random number, or key andperforming the same cryptographic splitting of the key used in theencryption of splitting of the data to be secured into two or moreportions, or shares, of parsed and split data, and in one embodiment,preferably into four or more portions of parsed and split data,encrypting all of the portions, then scattering and storing theseportions back into the database, or relocating them to any named device,fixed or removable, depending on the requestor's need for privacy andsecurity. Alternatively, in another embodiment, encryption may occurprior to the splitting of the data set by the splitting module or securedata parser. The original data processed as described in this embodimentis encrypted and obfuscated and is secured. The dispersion of theencrypted elements, if desired, can be virtually anywhere, including,but not limited to, a single server or data storage device, or amongseparate data storage facilities or devices. Encryption key managementin one embodiment may be included within the software suite, or inanother embodiment may be integrated into an existing infrastructure orany other desired location.

A cryptographic split (cryptosplit) partitions the data into N number ofshares. The partitioning can be on any size unit of data, including anindividual bit, bits, bytes, kilobytes, megabytes, or larger units, aswell as any pattern or combination of data unit sizes whetherpredetermined or randomly generated. The units can also be of differentsized, based on either a random or predetermined set of values. Thismeans the data can be viewed as a sequence of these units. In thismanner the size of the data units themselves may render the data moresecure, for example by using one or more predetermined or randomlygenerated pattern, sequence or combination of data unit sizes. The unitsare then distributed (either randomly or by a predetermined set ofvalues) into the N shares. This distribution could also involve ashuffling of the order of the units in the shares. It is readilyapparent to those of ordinary skill in the art that the distribution ofthe data units into the shares may be performed according to a widevariety of possible selections, including but not limited to size-fixed,predetermined sizes, or one or more combination, pattern or sequence ofdata unit sizes that are predetermined or randomly generated.

In some embodiments of this cryptosplit split process, the data may beany suitable number of bytes in size, such as one, two, three, five,twenty, fifty, one hundred, more than one hundred, or N bytes in size.One particular example of this cryptographic split process, orcryptosplit, would be to consider the data to be 23 bytes in size, withthe data unit size chosen to be one byte, and with the number of sharesselected to be 4. Each byte would be distributed into one of the 4shares. Assuming a random distribution, a key would be obtained tocreate a sequence of 23 random numbers (r1, r2, r3 through r23), eachwith a value between 1 and 4 corresponding to the four shares. Each ofthe units of data (in this example 23 individual bytes of data) isassociated with one of the 23 random numbers corresponding to one of thefour shares. The distribution of the bytes of data into the four shareswould occur by placing the first byte of the data into share number r1,byte two into share r2, byte three into share r3, through the 23^(rd)byte of data into share r23. It is readily apparent to those of ordinaryskill in the art that a wide variety of other possible steps orcombination or sequence of steps, including the size of the data units,may be used in the cryptosplit process of the present invention, and theabove example is a non-limiting description of one process forcryptosplitting data. To recreate the original data, the reverseoperation would be performed.

In another embodiment of the cryptosplit process of the presentinvention, an option for the cryptosplitting process is to providesufficient redundancy in the shares such that only a subset of theshares are needed to reassemble or restore the data to its original oruseable form. As a non-limiting example, the cryptosplit may be done asa “3 of 4” cryptosplit such that only three of the four shares arenecessary to reassemble or restore the data to its original or useableform. This is also referred to as a “M of N cryptosplit” wherein N isthe total number of shares, and M is at least one less than N. It isreadily apparent to those of ordinary skill in the art that there aremany possibilities for creating this redundancy in the cryptosplittingprocess of the present invention.

In one embodiment of the cryptosplitting process of the presentinvention, each unit of data is stored in two shares, the primary shareand the backup share. Using the “3 of 4” cryptosplitting processdescribed above, any one share can be missing, and this is sufficient toreassemble or restore the original data with no missing data units sinceonly three of the total four shares are required. As described herein, arandom number is generated that corresponds to one of the shares. Therandom number is associated with a data unit, and stored in thecorresponding share, based on a key. One key is used, in thisembodiment, to generate the primary and backup share random number. Asdescribed herein for the cryptosplitting process of the presentinvention, a set of random numbers (also referred to as primary sharenumbers) from 0 to 3 are generated equal to the number of data units.Then another set of random numbers is generated (also referred to asbackup share numbers) from 1 to 3 equal to the number of data units.Each unit of data is then associated with a primary share number and abackup share number. Alternatively, a set of random numbers may begenerated that is fewer than the number of data units, and repeating therandom number set, but this may reduce the security of the sensitivedata. The primary share number is used to determine into which share thedata unit is stored. The backup share number is combined with theprimary share number to create a third share number between 0 and 3, andthis number is used to determine into which share the data unit isstored. In this example, the equation to determine the third sharenumber is:(primary share number+backup share number)MOD 4=third share number.

In the embodiment described above where the primary share number isbetween 0 and 3, and the backup share number is between 1 and 3 ensuresthat the third share number is different from the primary share number.This results in the data unit being stored in two different shares. Itis readily apparent to those of ordinary skill in the art that there aremany ways of performing redundant cryptosplitting and non-redundantcryptosplitting in addition to the embodiments disclosed herein. Forexample, the data units in each share could be shuffled utilizing adifferent algorithm. This data unit shuffling may be performed as theoriginal data is split into the data units, or after the data units areplaced into the shares, or after the share is full, for example.

The various cryptosplitting processes and data shuffling processesdescribed herein, and all other embodiments of the cryptosplitting anddata shuffling methods of the present invention may be performed on dataunits of any size, including but not limited to, as small as anindividual bit, bits, bytes, kilobytes, megabytes or larger.

An example of one embodiment of source code that would perform thecryptosplitting process described herein is:

DATA [1:24] - array of bytes with the data to be split SHARES[0:3;1:24] - 2-dimensionalarray with each row representing one of the sharesRANDOM[1:24] - array random numbers in the range of 0..3 S1 = 1; S2 = 1;S3 = 1; S4 = 1; For J = 1 to 24 do Begin IF RANDOM[J[ ==0 then BeginSHARES[1,S1] = DATA [J]; S1 = S1 + 1; End ELSE IF RANDOM[J[ ==1 thenBegin SHARES[2,S2] = DATA [J]; S2 = S2 + 1; END ELSE IF RANDOM[J[ ==2then Begin Shares[3,S3] = data [J]; S3 = S3 + 1; End Else beginShares[4,S4] = data [J]; S4 = S4 + 1; End; END;

An example of one embodiment of source code that would perform thecryptosplitting RAID process described herein is:

Generate two sets of numbers, PrimaryShare is 0 to 3, BackupShare is 1to 3. Then put each data unit into share[primaryshare[1]] andshare[(primaryshare[1]+backupshare[1]) mod 4, with the same process asin cryptosplitting described above. This method will be scalable to anysize N, where only N−1 shares are necessary to restore the data.

The retrieval, recombining, reassembly or reconstituting of theencrypted data elements may utilize any number of authenticationtechniques, including, but not limited to, biometrics, such asfingerprint recognition, facial scan, hand scan, iris scan, retinalscan, ear scan, vascular pattern recognition or DNA analysis. The datasplitting and/or parser modules of the present invention may beintegrated into a wide variety of infrastructure products orapplications as desired.

Traditional encryption technologies known in the art rely on one or morekey used to encrypt the data and render it unusable without the key. Thedata, however, remains whole and intact and subject to attack. Thesecure data parser of the present invention, in one embodiment,addresses this problem by performing a cryptographic parsing andsplitting of the encrypted file into two or more portions or shares, andin another embodiment, preferably four or more shares, adding anotherlayer of encryption to each share of the data, then storing the sharesin different physical and/or logical locations. When one or more datashares are physically removed from the system, either by using aremovable device, such as a data storage device, or by placing the shareunder another party's control, any possibility of compromise of secureddata is effectively removed.

An example of one embodiment of the secure data parser of the presentinvention and an example of how it may be utilized is shown in FIG. 21and described below. However, it is readily apparent to those ofordinary skill in the art that the secure data parser of the presentinvention may be utilized in a wide variety of ways in addition to thenon-limiting example below. As a deployment option, and in oneembodiment, the secure data parser may be implemented with externalsession key management or secure internal storage of session keys. Uponimplementation, a Parser Master Key will be generated which will be usedfor securing the application and for encryption purposes. It should bealso noted that the incorporation of the Parser Master key in theresulting secured data allows for a flexibility of sharing of secureddata by individuals within a workgroup, enterprise or extended audience.

As shown in FIG. 21, this embodiment of the present invention shows thesteps of the process performed by the secure data parser on data tostore the session master key with the parsed data:

1. Generating a session master key and encrypt the data using RS1 streamcipher.

2. Separating the resulting encrypted data into four shares or portionsof parsed data according to the pattern of the session master key.

3. In this embodiment of the method, the session master key will bestored along with the secured data shares in a data depository.Separating the session master key according to the pattern of the ParserMaster Key and append the key data to the encrypted parsed data.

4. The resulting four shares of data will contain encrypted portions ofthe original data and portions of the session master key. Generate astream cipher key for each of the four data shares.

5. Encrypting each share, then store the encryption keys in differentlocations from the encrypted data portions or shares: Share 1 gets Key4, Share 2 gets Key 1, Share 3 gets Key 2, Share 4 gets Key 3.

To restore the original data format, the steps are reversed.

It is readily apparent to those of ordinary skill in the art thatcertain steps of the methods described herein may be performed indifferent order, or repeated multiple times, as desired. It is alsoreadily apparent to those skilled in the art that the portions of thedata may be handled differently from one another. For example, multipleparsing steps may be performed on only one portion of the parsed data.Each portion of parsed data may be uniquely secured in any desirable wayprovided only that the data may be reassembled, reconstituted, reformed,decrypted or restored to its original or other usable form.

As shown in FIG. 22 and described herein, another embodiment of thepresent invention comprises the steps of the process performed by thesecure data parser on data to store the session master key data in oneor more separate key management table:

1. Generating a session master key and encrypt the data using RS1 streamcipher.

2. Separating the resulting encrypted data into four shares or portionsof parsed data according to the pattern of the session master key.

3. In this embodiment of the method of the present invention, thesession master key will be stored in a separate key management table ina data depository. Generating a unique transaction ID for thistransaction. Storing the transaction ID and session master key in aseparate key management table. Separating the transaction ID accordingto the pattern of the Parser Master Key and append the data to theencrypted parsed or separated data.

4. The resulting four shares of data will contain encrypted portions ofthe original data and portions of the transaction ID.

5. Generating a stream cipher key for each of the four data shares.

6. Encrypting each share, then store the encryption keys in differentlocations from the encrypted data portions or shares: Share 1 gets Key4, Share 2 gets Key 1, Share 3 gets Key 2, Share 4 gets Key 3.

To restore the original data format, the steps are reversed.

It is readily apparent to those of ordinary skill in the art thatcertain steps of the method described herein may be performed indifferent order, or repeated multiple times, as desired. It is alsoreadily apparent to those skilled in the art that the portions of thedata may be handled differently from one another. For example, multipleseparating or parsing steps may be performed on only one portion of theparsed data. Each portion of parsed data may be uniquely secured in anydesirable way provided only that the data may be reassembled,reconstituted, reformed, decrypted or restored to its original or otherusable form.

As shown in FIG. 23, this embodiment of the present invention shows thesteps of the process performed by the secure data parser on data tostore the session master key with the parsed data:

1. Accessing the parser master key associated with the authenticateduser

2. Generating a unique Session Master key

3. Derive an Intermediary Key from an exclusive OR function of theParser Master Key and Session Master key

4. Optional encryption of the data using an existing or new encryptionalgorithm keyed with the Intermediary Key.

5. Separating the resulting optionally encrypted data into four sharesor portions of parsed data according to the pattern of the Intermediarykey.

6. In this embodiment of the method, the session master key will bestored along with the secured data shares in a data depository.Separating the session master key according to the pattern of the ParserMaster Key and append the key data to the optionally encrypted parseddata shares.

7. The resulting multiple shares of data will contain optionallyencrypted portions of the original data and portions of the sessionmaster key.

8. Optionally generate an encryption key for each of the four datashares.

9. Optionally encrypting each share with an existing or new encryptionalgorithm, then store the encryption keys in different locations fromthe encrypted data portions or shares: for example, Share 1 gets Key 4,Share 2 gets Key 1, Share 3 gets Key 2, Share 4 gets Key 3.

To restore the original data format, the steps are reversed.

It is readily apparent to those of ordinary skill in the art thatcertain steps of the methods described herein may be performed indifferent order, or repeated multiple times, as desired. It is alsoreadily apparent to those skilled in the art that the portions of thedata may be handled differently from one another. For example, multipleparsing steps may be performed on only one portion of the parsed data.Each portion of parsed data may be uniquely secured in any desirable wayprovided only that the data may be reassembled, reconstituted, reformed,decrypted or restored to its original or other usable form.

As shown in FIG. 24 and described herein, another embodiment of thepresent invention comprises the steps of the process performed by thesecure data parser on data to store the session master key data in oneor more separate key management table:

1. Accessing the Parser Master Key associated with the authenticateduser

2. Generating a unique Session Master Key

3. Derive an Intermediary Key from an exclusive OR function of theParser Master Key and Session Master key

4. Optionally encrypt the data using an existing or new encryptionalgorithm keyed with the Intermediary Key.

5. Separating the resulting optionally encrypted data into four sharesor portions of parsed data according to the pattern of the IntermediaryKey.

6. In this embodiment of the method of the present invention, thesession master key will be stored in a separate key management table ina data depository. Generating a unique transaction ID for thistransaction. Storing the transaction ID and session master key in aseparate key management table or passing the Session Master Key andtransaction ID back to the calling program for external management.Separating the transaction ID according to the pattern of the ParserMaster Key and append the data to the optionally encrypted parsed orseparated data.

7. The resulting four shares of data will contain optionally encryptedportions of the original data and portions of the transaction ID.

8. Optionally generate an encryption key for each of the four datashares.

9. Optionally encrypting each share, then store the encryption keys indifferent locations from the encrypted data portions or shares. Forexample: Share 1 gets Key 4, Share 2 gets Key 1, Share 3 gets Key 2,Share 4 gets Key 3.

To restore the original data format, the steps are reversed.

It is readily apparent to those of ordinary skill in the art thatcertain steps of the method described herein may be performed indifferent order, or repeated multiple times, as desired. It is alsoreadily apparent to those skilled in the art that the portions of thedata may be handled differently from one another. For example, multipleseparating or parsing steps may be performed on only one portion of theparsed data. Each portion of parsed data may be uniquely secured in anydesirable way provided only that the data may be reassembled,reconstituted, reformed, decrypted or restored to its original or otherusable form.

A wide variety of encryption methodologies are suitable for use in themethods of the present invention, as is readily apparent to thoseskilled in the art. The One Time Pad algorithm, is often considered oneof the most secure encryption methods, and is suitable for use in themethod of the present invention. Using the One Time Pad algorithmrequires that a key be generated which is as long as the data to besecured. The use of this method may be less desirable in certaincircumstances such as those resulting in the generation and managementof very long keys because of the size of the data set to be secured. Inthe One-Time Pad (OTP) algorithm, the simple exclusive-or function, XOR,is used. For two binary streams x and y of the same length, x XOR ymeans the bitwise exclusive-or of x and y.

At the bit level is generated:0 XOR 0=00 XOR 1=11 XOR 0=11 XOR 1=0

An example of this process is described herein for an n-byte secret, s,(or data set) to be split. The process will generate an n-byte randomvalue, a, and then set:b=a XOR s.

Note that one can derive “s” via the equation:s=a XOR b.

The values a and b are referred to as shares or portions and are placedin separate depositories. Once the secret s is split into two or moreshares, it is discarded in a secure manner.

The secure data parser of the present invention may utilize thisfunction, performing multiple XOR functions incorporating multipledistinct secret key values: K1, K2, K3, Kn, K5. At the beginning of theoperation, the data to be secured is passed through the first encryptionoperation, secure data=data XOR secret key 5:S=D XOR K5

In order to securely store the resulting encrypted data in, for example,four shares, S1, S2, S3, Sn, the data is parsed and split into “n”segments, or shares, according to the value of K5. This operationresults in “n” pseudorandom shares of the original encrypted data.Subsequent XOR functions may then be performed on each share with theremaining secret key values, for example: Secure data segment1=encrypted data share 1 XOR secret key 1:SD1=S1 XOR K1SD2=S2 XOR K2SD3=S3 XOR K3SDn=Sn XOR Kn.

In one embodiment, it may not be desired to have any one depositorycontain enough information to decrypt the information held there, so thekey required to decrypt the share is stored in a different datadepository:

Depository 1: SD1, Kn

Depository 2: SD2, K1

Depository 3: SD3, K2

Depository n: SDn, K3.

Additionally, appended to each share may be the information required toretrieve the original session encryption key, K5. Therefore, in the keymanagement example described herein, the original session master key isreferenced by a transaction ID split into “n” shares according to thecontents of the installation dependant Parser Master Key (TID1, TID2,TID3, TIDn):

Depository 1: SD1, Kn, TID1

Depository 2: SD2, K1, TID2

Depository 3: SD3, K2, TID3

Depository n: SDn, K3, TIDn.

In the incorporated session key example described herein, the sessionmaster key is split into “n” shares according to the contents of theinstallation dependant Parser Master Key (SK1, SK2, SK3, SKn):

Depository 1: SD1, Kn, SK1

Depository 2: SD2, K1, SK2

Depository 3: SD3, K2, SK3

Depository n: SDn, K3, SKn.

Unless all four shares are retrieved, the data cannot be reassembledaccording to this example. Even if all four shares are captured, thereis no possibility of reassembling or restoring the original informationwithout access to the session master key and the Parser Master Key.

This example has described an embodiment of the method of the presentinvention, and also describes, in another embodiment, the algorithm usedto place shares into depositories so that shares from all depositoriescan be combined to form the secret authentication material. Thecomputations needed are very simple and fast. However, with the One TimePad (OTP) algorithm there may be circumstances that cause it to be lessdesirable, such as a large data set to be secured, because the key sizeis the same size as the data to be stored. Therefore, there would be aneed to store and transmit about twice the amount of the original datawhich may be less desirable under certain circumstances.

Stream Cipher RS1

The stream cipher RS1 splitting technique is very similar to the OTPsplitting technique described herein. Instead of an n-byte random value,an n′=min(n, 16)-byte random value is generated and used to key the RS1Stream Cipher algorithm. The advantage of the RS1 Stream Cipheralgorithm is that a pseudorandom key is generated from a much smallerseed number. The speed of execution of the RS1 Stream Cipher encryptionis also rated at approximately 10 times the speed of the well known inthe art Triple Data Encryption Standard (“Triple DES” or “3DES”)encryption without compromising security. The RS1 Stream Cipheralgorithm is well known in the art, and may be used to generate the keysused in the XOR function. The RS1 Stream Cipher algorithm isinteroperable with other commercially available stream cipheralgorithms, such as the RC4™ stream cipher algorithm of RSA Security,Inc and is suitable for use in the methods of the present invention.

Using the key notation above, K1 thru K5 are now an n′ byte randomvalues and we set:SD1=S1 XOR E(K1)SD2=S2 XOR E(K2)SD3=S3 XOR E(K3)SDn=Sn XOR E(Kn)where E(K1) thru E(Kn) are the first n′ bytes of output from the RS1Stream Cipher algorithm keyed by K1 thru Kn. The shares are now placedinto data depositories as described herein.

In this stream cipher RS1 algorithm, the required computations neededare nearly as simple and fast as the OTP algorithm. The benefit in thisexample using the RS1 Stream Cipher is that the system needs to storeand transmit on average only about 16 bytes more than the size of theoriginal data to be secured per share. When the size of the originaldata is more than 16 bytes, this RS1 algorithm is more efficient thanthe OTP algorithm because it is simply shorter. It is readily apparentto those of ordinary skill in the art that a wide variety of encryptionmethods or algorithms are suitable for use in the present invention,including, but not limited to RS1, OTP, RC4™, Triple DES, and theAdvanced Encryption Standard (“AES”).

There are major advantages provided by the data security methods andcomputer systems of the present invention over traditional encryptionmethods. One advantage is the security gained from moving shares of thedata to different locations on one or more data depositories or storagedevices, that may be in different logical, physical or geographicallocations. When the shares of data are split physically and under thecontrol of different personnel, for example, the possibility ofcompromising the data is greatly reduced.

Another advantage provided by the methods and system of the presentinvention is the combination of the steps of the method of the presentinvention for securing data to provide a comprehensive process ofmaintaining security of sensitive data. The data is encrypted with asecure key and split into one or more shares, and in one embodiment,four shares, according to the secure key. The secure key is storedsafely with a reference pointer which is secured into four sharesaccording to a secure key. The data shares are then encryptedindividually and the keys are stored safely with different encryptedshares. When combined, the entire process for securing data according tothe methods disclosed herein becomes a comprehensive package for datasecurity.

The data secured according to the methods of the present invention isreadily retrievable and restored, reconstituted, reassembled, decrypted,or otherwise returned into its original or other suitable form for use.In order to restore the original data, the following items may beutilized:

1. All shares or portions of the data set.

2. Knowledge of and ability to reproduce the process flow of the methodused to secure the data.

3. Access to the session master key.

4. Access to the Parser Master Key.

Therefore, it may be desirable to plan a secure installation wherein atleast one of the above elements may be physically separated from theremaining components of the system (under the control of a differentsystem administrator for example).

Protection against a rogue application invoking the data securingmethods application may be enforced by use of the Parser Master Key. Amutual authentication handshake between the secure data parser and theapplication may be required in this embodiment of the present inventionprior to any action taken.

The security of the system dictates that there be no “backdoor” methodfor recreation of the original data. For installations where datarecovery issues may arise, the secure data parser can be enhanced toprovide a mirror of the four shares and session master key depository.Hardware options such as RAID (redundant array of inexpensive disks,used to spread information over several disks) and software options suchas replication can assist as well in the data recovery planning.

Key Management

In one embodiment of the present invention, the data securing methoduses three sets of keys for an encryption operation. Each set of keysmay have individual key storage, retrieval, security and recoveryoptions, based on the installation. The keys that may be used, include,but are not limited to:

The Parser Master Key

This key is an individual key associated with the installation of thesecure data parser. It is installed on the server on which the securedata parser has been deployed. There are a variety of options suitablefor securing this key including, but not limited to, a smart card,separate hardware key store, standard key stores, custom key stores orwithin a secured database table, for example.

The Session Master Key

A Session Master Key may be generated each time data is secured. TheSession Master Key is used to encrypt the data prior to the parsing andsplitting operations. It may also be incorporated (if the Session MasterKey is not integrated into the parsed data) as a means of parsing theencrypted data. The Session Master Key may be secured in a variety ofmanners, including, but not limited to, a standard key store, custom keystore, separate database table, or secured within the encrypted shares,for example.

The Share Encryption Keys

For each share or portions of a data set that is created, an individualShare Encryption Key may be generated to further encrypt the shares. TheShare Encryption Keys may be stored in different shares than the sharethat was encrypted.

It is readily apparent to those of ordinary skill in the art that thedata securing methods and computer system of the present invention arewidely applicable to any type of data in any setting or environment. Inaddition to commercial applications conducted over the Internet orbetween customers and vendors, the data securing methods and computersystems of the present invention are highly applicable to non-commercialor private settings or environments. Any data set that is desired to bekept secure from any unauthorized user may be secured using the methodsand systems described herein. For example, access to a particulardatabase within a company or organization may be advantageouslyrestricted to only selected users by employing the methods and systemsof the present invention for securing data. Another example is thegeneration, modification or access to documents wherein it is desired torestrict access or prevent unauthorized or accidental access ordisclosure outside a group of selected individuals, computers orworkstations. These and other examples of the ways in which the methodsand systems of data securing of the present invention are applicable toany non-commercial or commercial environment or setting for any setting,including, but not limited to any organization, government agency orcorporation.

In another embodiment of the present invention, the data securing methoduses three sets of keys for an encryption operation. Each set of keysmay have individual key storage, retrieval, security and recoveryoptions, based on the installation. The keys that may be used, include,but are not limited to:

1. The Parser Master Key

This key is an individual key associated with the installation of thesecure data parser. It is installed on the server on which the securedata parser has been deployed. There are a variety of options suitablefor securing this key including, but not limited to, a smart card,separate hardware key store, standard key stores, custom key stores orwithin a secured database table, for example.

2. The Session Master Key

A Session Master Key may be generated each time data is secured. TheSession Master Key is used in conjunction with the Parser Master key toderive the Intermediary Key. The Session Master Key may be secured in avariety of manners, including, but not limited to, a standard key store,custom key store, separate database table, or secured within theencrypted shares, for example.

3. The Intermediary Key

An Intermediary Key may be generated each time data is secured. TheIntermediary Key is used to encrypt the data prior to the parsing andsplitting operation. It may also be incorporated as a means of parsingthe encrypted data.

4. The Share Encryption Keys

For each share or portions of a data set that is created, an individualShare Encryption Key may be generated to further encrypt the shares. TheShare Encryption Keys may be stored in different shares than the sharethat was encrypted.

It is readily apparent to those of ordinary skill in the art that thedata securing methods and computer system of the present invention arewidely applicable to any type of data in any setting or environment. Inaddition to commercial applications conducted over the Internet orbetween customers and vendors, the data securing methods and computersystems of the present invention are highly applicable to non-commercialor private settings or environments. Any data set that is desired to bekept secure from any unauthorized user may be secured using the methodsand systems described herein. For example, access to a particulardatabase within a company or organization may be advantageouslyrestricted to only selected users by employing the methods and systemsof the present invention for securing data. Another example is thegeneration, modification or access to documents wherein it is desired torestrict access or prevent unauthorized or accidental access ordisclosure outside a group of selected individuals, computers orworkstations. These and other examples of the ways in which the methodsand systems of data securing of the present invention are applicable toany non-commercial or commercial environment or setting for any setting,including, but not limited to any organization, government agency orcorporation.

Workgroup, Project, Individual PC/Laptop or Cross Platform Data Security

The data securing methods and computer systems of the present inventionare also useful in securing data by workgroup, project, individualPC/Laptop and any other platform that is in use in, for example,businesses, offices, government agencies, or any setting in whichsensitive data is created, handled or stored. The present inventionprovides methods and computer systems to secure data that is known to besought after by organizations, such as the U.S. Government, forimplementation across the entire government organization or betweengovernments at a state or federal level.

The data securing methods and computer systems of the present inventionprovide the ability to not only parse and split flat files but also datafields, sets and or table of any type. Additionally, all forms of dataare capable of being secured under this process, including, but notlimited to, text, video, images, biometrics and voice data. Scalability,speed and data throughput of the methods of securing data of the presentinvention are only limited to the hardware the user has at theirdisposal.

In one embodiment of the present invention, the data securing methodsare utilized as described below in a workgroup environment. In oneembodiment, as shown in FIG. 23 and described below, the Workgroup Scaledata securing method of the present invention uses the private keymanagement functionality of the TrustEngine to store the user/grouprelationships and the associated private keys (Parser Group Master Keys)necessary for a group of users to share secure data. The method of thepresent invention has the capability to secure data for an enterprise,workgroup, or individual user, depending on how the Parser Master Keywas deployed.

In one embodiment, additional key management and user/group managementprograms may be provided, enabling wide scale workgroup implementationwith a single point of administration and key management. Keygeneration, management and revocation are handled by the singlemaintenance program, which all become especially important as the numberof users increase. In another embodiment, key management may also be setup across one or several different system administrators, which may notallow any one person or group to control data as needed. This allows forthe management of secured data to be obtained by roles,responsibilities, membership, rights, etc., as defined by anorganization, and the access to secured data can be limited to justthose who are permitted or required to have access only to the portionthey are working on, while others, such as managers or executives, mayhave access to all of the secured data. This embodiment allows for thesharing of secured data among different groups within a company ororganization while at the same time only allowing certain selectedindividuals, such as those with the authorized and predetermined rolesand responsibilities, to observe the data as a whole. In addition, thisembodiment of the methods and systems of the present invention alsoallows for the sharing of data among, for example, separate companies,or separate departments or divisions of companies, or any separateorganization departments, groups, agencies, or offices, or the like, ofany government or organization or any kind, where some sharing isrequired, but not any one party may be permitted to have access to allthe data. Particularly apparent examples of the need and utility forsuch a method and system of the present invention are to allow sharing,but maintain security, in between government areas, agencies andoffices, and between different divisions, departments or offices of alarge company, or any other organization, for example.

An example of the applicability of the methods of the present inventionon a smaller scale is as follows. A Parser Master key is used as aserialization or branding of the secure data parser to an organization.As the scale of use of the Parser Master key is reduced from the wholeenterprise to a smaller workgroup, the data securing methods describedherein are used to share files within groups of users.

In the example shown in FIG. 25 and described below, there are six usersdefined along with their title or role within the organization. The sidebar represents five possible groups that the users can belong toaccording to their role. The arrow represents membership by the user inone or more of the groups.

When configuring the secure data parser for use in this example, thesystem administrator accesses the user and group information from theoperating system by a maintenance program. This maintenance programgenerates and assigns Parser Group Master Keys to users based on theirmembership in groups.

In this example, there are three members in the Senior Staff group. Forthis group, the actions would be:

1. Access Parser Group Master Key for the Senior Staff group (generate akey if not available);

2. Generate a digital certificate associating CEO with the Senior Staffgroup;

3. Generate a digital certificate associating CFO with the Senior Staffgroup;

4. Generate a digital certificate associating Vice President, Marketingwith the Senior Staff group.

The same set of actions would be done for each group, and each memberwithin each group. When the maintenance program is complete, the ParserGroup Master Key becomes a shared credential for each member of thegroup. Revocation of the assigned digital certificate may be doneautomatically when a user is removed from a group through themaintenance program without affecting the remaining members of thegroup.

Once the shared credentials have been defined, the parsing and splittingprocess remains the same. When a file, document or data element is to besecured, the user is prompted for the target group to be used whensecuring the data. The resulting secured data is only accessible byother members of the target group. This functionality of the methods andsystems of the present invention may be used with any other computersystem or software platform, any may be, for example, integrated intoexisting application programs or used standalone for file security.

It is readily apparent to those of ordinary skill in the art that anyone or combination of encryption algorithms are suitable for use in themethods and systems of the present invention. For example, theencryption steps may, in one embodiment, be repeated to produce amulti-layered encryption scheme. In addition, a different encryptionalgorithm, or combination of encryption algorithms, may be used inrepeat encryption steps such that different encryption algorithms areapplied to the different layers of the multi-layered encryption scheme.As such, the encryption scheme itself may become a component of themethods of the present invention for securing sensitive data fromunauthorized use or access.

The secure data parser may include as an internal component, as anexternal component, or as both an error-checking component. For example,in one suitable approach, as portions of data are created using thesecure data parser in accordance with the present invention, to assurethe integrity of the data within a portion, a hash value is taken atpreset intervals within the portion and is appended to the end of theinterval. The hash value is a predictable and reproducible numericrepresentation of the data. If any bit within the data changes, the hashvalue would be different. A scanning module (either as a stand-alonecomponent external to the secure data parser or as an internalcomponent) may then scan the portions of data generated by the securedata parser. Each portion of data (or alternatively, less than allportions of data according to some interval or by a random orpseudo-random sampling) is compared to the appended hash value or valuesand an action may be taken. This action may include a report of valuesthat match and do not match, an alert for values that do not match, orinvoking of some external or internal program to trigger a recovery ofthe data. For example, recovery of the data could be performed byinvoking a recovery module based on the concept that fewer than allportions may be needed to generate original data in accordance with thepresent invention.

Any other suitable integrity checking may be implemented using anysuitable integrity information appended anywhere in all or a subset ofdata portions. Integrity information may include any suitableinformation that can be used to determine the integrity of dataportions. Examples of integrity information may include hash valuescomputed based on any suitable parameter (e.g., based on respective dataportions), digital signature information, message authentication code(MAC) information, any other suitable information, or any combinationthereof.

The secure data parser of the present invention may be used in anysuitable application. Namely, the secure data parser described hereinhas a variety of applications in different areas of computing andtechnology. Several such areas are discussed below. It will beunderstood that these are merely illustrative in nature and that anyother suitable applications may make use of the secure data parser. Itwill further be understood that the examples described are merelyillustrative embodiments that may be modified in any suitable way inorder to satisfy any suitable desires. For example, parsing andsplitting may be based on any suitable units, such as by bits, by bytes,by kilobytes, by megabytes, by any combination thereof, or by any othersuitable unit.

The secure data parser of the present invention may be used to implementsecure physical tokens, whereby data stored in a physical token may berequired in order to access additional data stored in another storagearea. In one suitable approach, a physical token, such as a compact USBflash drive, a floppy disk, an optical disk, a smart card, or any othersuitable physical token, may be used to store one of at least twoportions of parsed data in accordance with the present invention. Inorder to access the original data, the USB flash drive would need to beaccessed. Thus, a personal computer holding one portion of parsed datawould need to have the USB flash drive, having the other portion ofparsed data, attached before the original data can be accessed. FIG. 26illustrates this application. Storage area 2500 includes a portion ofparsed data 2502. Physical token 2504, having a portion of parsed data2506 would need to be coupled to storage area 2500 using any suitablecommunications interface 2508 (e.g., USB, serial, parallel, Bluetooth,IR, IEEE 1394, Ethernet, or any other suitable communications interface)in order to access the original data. This is useful in a situationwhere, for example, sensitive data on a computer is left alone andsubject to unauthorized access attempts. By removing the physical token(e.g., the USB flash drive), the sensitive data is inaccessible. It willbe understood that any other suitable approach for using physical tokensmay be used.

The secure data parser of the present invention may be used to implementa secure authentication system whereby user enrollment data (e.g.,passwords, private encryption keys, fingerprint templates, biometricdata or any other suitable user enrollment data) is parsed and splitusing the secure data parser. The user enrollment data may be parsed andsplit whereby one or more portions are stored on a smart card, agovernment Common Access Card, any suitable physical storage device(e.g., magnetic or optical disk, USB key drive, etc.), or any othersuitable device. One or more other portions of the parsed userenrollment data may be stored in the system performing theauthentication. This provides an added level of security to theauthentication process (e.g., in addition to the biometricauthentication information obtained from the biometric source, the userenrollment data must also be obtained via the appropriate parsed andsplit data portion).

The secure data parser of the present invention may be integrated intoany suitable existing system in order to provide the use of itsfunctionality in each system's respective environment. FIG. 27 shows ablock diagram of an illustrative system 2600, which may includesoftware, hardware, or both for implementing any suitable application.System 2600 may be an existing system in which secure data parser 2602may be retrofitted as an integrated component. Alternatively, securedata parser 2602 may be integrated into any suitable system 2600 from,for example, its earliest design stage. Secure data parser 2600 may beintegrated at any suitable level of system 2600. For example, securedata parser 2602 may be integrated into system 2600 at a sufficientlyback-end level such that the presence of secure data parser 2602 may besubstantially transparent to an end user of system 2600. Secure dataparser 2602 may be used for parsing and splitting data among one or morestorage devices 2604 in accordance with the present invention. Someillustrative examples of systems having the secure data parserintegrated therein are discussed below.

The secure data parser of the present invention may be integrated intoan operating system kernel (e.g., Linux, Unix, or any other suitablecommercial or proprietary operating system). This integration may beused to protect data at the device level whereby, for example, data thatwould ordinarily be stored in one or more devices is separated into acertain number of portions by the secure data parser integrated into theoperating system and stored among the one or more devices. When originaldata is attempted to be accessed, the appropriate software, alsointegrated into the operating system, may recombine the parsed dataportions into the original data in a way that may be transparent to theend user.

The secure data parser of the present invention may be integrated into avolume manager or any other suitable component of a storage system toprotect local and networked data storage across any or all supportedplatforms. For example, with the secure data parser integrated, astorage system may make use of the redundancy offered by the secure dataparser (i.e., which is used to implement the feature of needing fewerthan all separated portions of data in order to reconstruct the originaldata) to protect against data loss. The secure data parser also allowsall data written to storage devices, whether using redundancy or not, tobe in the form of multiple portions that are generated according to theparsing of the present invention. When original data is attempted to beaccessed, the appropriate software, also integrated into the volumemanager or other suitable component of the storage system, may recombinethe parsed data portions into the original data in a way that may betransparent to the end user.

In one suitable approach, the secure data parser of the presentinvention may be integrated into a RAID controller (as either hardwareor software). This allows for the secure storage of data to multipledrives while maintaining fault tolerance in case of drive failure.

The secure data parser of the present invention may be integrated into adatabase in order to, for example, protect sensitive table information.For example, in one suitable approach, data associated with particularcells of a database table (e.g., individual cells, one or moreparticular columns, one or more particular rows, any combinationthereof, or an entire database table) may be parsed and separatedaccording to the present invention (e.g., where the different portionsare stored on one or more storage devices at one or more locations or ona single storage device). Access to recombine the portions in order toview the original data may be granted by traditional authenticationmethods (e.g., username and password query).

The secure data parser of the present invention may be integrated in anysuitable system that involves data in motion (i.e., transfer of datafrom one location to another). Such systems include, for example, email,streaming data broadcasts, and wireless (e.g., WiFi) communications.With respect to email, in one suitable approach, the secure data parsermay be used to parse outgoing messages (i.e., containing text, binarydata, or both (e.g., files attached to an email message)) and sendingthe different portions of the parsed data along different paths thuscreating multiple streams of data. If any one of these streams of datais compromised, the original message remains secure because the systemmay require that more than one of the portions be combined, inaccordance with the present invention, in order to generate the originaldata. In another suitable approach, the different portions of data maybe communicated along one path sequentially so that if one portion isobtained, it may not be sufficient to generate the original data. Thedifferent portions arrive at the intended recipient's location and maybe combined to generate the original data in accordance with the presentinvention.

FIGS. 28 and 29 are illustrative block diagrams of such email systems.FIG. 28 shows a sender system 2700, which may include any suitablehardware, such as a computer terminal, personal computer, handhelddevice (e.g., PDA, Blackberry), cellular telephone, computer network,any other suitable hardware, or any combination thereof. Sender system2700 is used to generate and/or store a message 2704, which may be, forexample, an email message, a binary data file (e.g., graphics, voice,video, etc.), or both. Message 2704 is parsed and split by secure dataparser 2702 in accordance with the present invention. The resultant dataportions may be communicated across one or more separate communicationspaths 2706 over network 2708 (e.g., the Internet, an intranet, a LAN,WiFi, Bluetooth, any other suitable hard-wired or wirelesscommunications means, or any combination thereof) to recipient system2710. The data portions may be communicated parallel in time oralternatively, according to any suitable time delay between thecommunication of the different data portions. Recipient system 2710 maybe any suitable hardware as described above with respect to sendersystem 2700. The separate data portions carried along communicationspaths 2706 are recombined at recipient system 2710 to generate theoriginal message or data in accordance with the present invention.

FIG. 29 shows a sender system 2800, which may include any suitablehardware, such as a computer terminal, personal computer, handhelddevice (e.g., PDA), cellular telephone, computer network, any othersuitable hardware, or any combination thereof. Sender system 2800 isused to generate and/or store a message 2804, which may be, for example,an email message, a binary data file (e.g., graphics, voice, video,etc.), or both. Message 2804 is parsed and split by secure data parser2802 in accordance with the present invention. The resultant dataportions may be communicated across a single communications paths 2806over network 2808 (e.g., the Internet, an intranet, a LAN, WiFi,Bluetooth, any other suitable communications means, or any combinationthereof) to recipient system 2810. The data portions may be communicatedserially across communications path 2806 with respect to one another.Recipient system 2810 may be any suitable hardware as described abovewith respect to sender system 2800. The separate data portions carriedalong communications path 2806 are recombined at recipient system 2810to generate the original message or data in accordance with the presentinvention.

It will be understood that the arrangement of FIGS. 28 and 29 are merelyillustrative. Any other suitable arrangement may be used. For example,in another suitable approach, the features of the systems of FIGS. 28and 29 may be combined whereby the multi-path approach of FIG. 28 isused and in which one or more of communications paths 2706 are used tocarry more than one portion of data as communications path 2806 does inthe context of FIG. 29.

The secure data parser may be integrated at any suitable level of adata-in motion system. For example, in the context of an email system,the secure data parser may be integrated at the user-interface level(e.g., into Microsoft® Outlook), in which case the user may have controlover the use of the secure data parser features when using email.Alternatively, the secure data parser may be implemented in a back-endcomponent such as at the exchange server, in which case messages may beautomatically parsed, split, and communicated along different paths inaccordance with the present invention without any user intervention.

Similarly, in the case of streaming broadcasts of data (e.g., audio,video), the outgoing data may be parsed and separated into multiplestreams each containing a portion of the parsed data. The multiplestreams may be transmitted along one or more paths and recombined at therecipient's location in accordance with the present invention. One ofthe benefits of this approach is that it avoids the relatively largeoverhead associated with traditional encryption of data followed bytransmission of the encrypted data over a single communications channel.The secure data parser of the present invention allows data in motion tobe sent in multiple parallel streams, increasing speed and efficiency.

It will be understand that the secure data parser may be integrated forprotection of and fault tolerance of any type of data in motion throughany transport medium, including, for example, wired, wireless, orphysical. For example, voice over Internet protocol (VoIP) applicationsmay make use of the secure data parser of the present invention.Wireless or wired data transport from or to any suitable personaldigital assistant (PDA) devices such as Blackberries and SmartPhones maybe secured using the secure data parser of the present invention.Communications using wireless 802.11 protocols for peer to peer and hubbased wireless networks, satellite communications, point to pointwireless communications, Internet client/server communications, or anyother suitable communications may involve the data in motioncapabilities of the secure data parser in accordance with the presentinvention. Data communication between computer peripheral device (e.g.,printer, scanner, monitor, keyboard, network router, biometricauthentication device (e.g., fingerprint scanner), or any other suitableperipheral device) between a computer and a computer peripheral device,between a computer peripheral device and any other suitable device, orany combination thereof may make use of the data in motion features ofthe present invention.

The data in motion features of the present invention may also apply tophysical transportation of secure shares using for example, separateroutes, vehicles, methods, any other suitable physical transportation,or any combination thereof. For example, physical transportation of datamay take place on digital/magnetic tapes, floppy disks, optical disks,physical tokens, USB drives, removable hard drives, consumer electronicdevices with flash memory (e.g., Apple IPODs or other MP3 players),flash memory, any other suitable medium used for transporting data, orany combination thereof.

The secure data parser of the present invention may provide securitywith the ability for disaster recovery. According to the presentinvention, fewer than all portions of the separated data generated bythe secure data parser may be necessary in order to retrieve theoriginal data. That is, out of m portions stored, n may be the minimumnumber of these m portions necessary to retrieve the original data,where n<=m. For example, if each of four portions is stored in adifferent physical location relative to the other three portions, then,if n=2 in this example, two of the locations may be compromised wherebydata is destroyed or inaccessible, and the original data may still beretrieved from the portions in the other two locations. Any suitablevalue for n or m may be used.

In addition, the n of m feature of the present invention may be used tocreate a “two man rule” whereby in order to avoid entrusting a singleindividual or any other entity with full access to what may be sensitivedata, two or more distinct entities, each with a portion of theseparated data parsed by the secure data parser of the present inventionmay need to agree to put their portions together in order to retrievethe original data.

The secure data parser of the present invention may be used to provide agroup of entities with a group-wide key that allows the group members toaccess particular information authorized to be accessed by thatparticular group. The group key may be one of the data portionsgenerated by the secure data parser in accordance with the presentinvention that may be required to be combined with another portioncentrally stored, for example in order to retrieve the informationsought. This feature allows for, for example, secure collaboration amonga group. It may be applied in for example, dedicated networks, virtualprivate networks, intranets, or any other suitable network.

Specific applications of this use of the secure data parser include, forexample, coalition information sharing in which, for example,multi-national friendly government forces are given the capability tocommunicate operational and otherwise sensitive data on a security levelauthorized to each respective country over a single network or a dualnetwork (i.e., as compared to the many networks involving relativelysubstantial manual processes currently used). This capability is alsoapplicable for companies or other organizations in which informationneeded to be known by one or more specific individuals (within theorganization or without) may be communicated over a single networkwithout the need to worry about unauthorized individuals viewing theinformation.

Another specific application includes a multi-level security hierarchyfor government systems. That is, the secure data parser of the presentinvention may provide for the ability to operate a government system atdifferent levels of classified information (e.g., unclassified,classified, secret, top secret) using a single network. If desired, morenetworks may be used (e.g., a separate network for top secret), but thepresent invention allows for substantially fewer than currentarrangement in which a separate network is used for each level ofclassification.

It will be understood that any combination of the above describedapplications of the secure data parser of the present invention may beused. For example, the group key application can be used together withthe data in motion security application (i.e., whereby data that iscommunicated over a network can only be accessed by a member of therespective group and where, while the data is in motion, it is splitamong multiple paths (or sent in sequential portions) in accordance withthe present invention).

The secure data parser of the present invention may be integrated intoany middleware application to enable applications to securely store datato different database products or to different devices withoutmodification to either the applications or the database. Middleware is ageneral term for any product that allows two separate and alreadyexisting programs to communicate. For example, in one suitable approach,middleware having the secure data parser integrated, may be used toallow programs written for a particular database to communicate withother databases without custom coding.

The secure data parser of the present invention may be implementedhaving any combination of any suitable capabilities, such as thosediscussed herein. In some embodiments of the present invention, forexample, the secure data parser may be implemented having only certaincapabilities whereas other capabilities may be obtained through the useof external software, hardware, or both interfaced either directly orindirectly with the secure data parser.

FIG. 30, for example, shows an illustrative implementation of the securedata parser as secure data parser 3000. Secure data parser 3000 may beimplemented with very few built-in capabilities. As illustrated, securedata parser 3000 may include built-in capabilities for parsing andsplitting data into portions (also referred to herein as shares) of datausing module 3002 in accordance with the present invention. Secure dataparser 3000 may also include built in capabilities for performingredundancy in order to be able to implement, for example, the m of nfeature described above (i.e., recreating the original data using fewerthan all shares of parsed and split data) using module 3004. Secure dataparser 3000 may also include share distribution capabilities usingmodule 3006 for placing the shares of data into buffers from which theyare sent for communication to a remote location, for storage, etc. inaccordance with the present invention. It will be understood that anyother suitable capabilities may be built into secure data parser 3000.

Assembled data buffer 3008 may be any suitable memory used to store theoriginal data (although not necessarily in its original form) that willbe parsed and split by secure data parser 3000. In a splittingoperation, assembled data buffer 3008 provides input to secure dataparser 3008. In a restore operation, assembled data buffer 3008 may beused to store the output of secure data parser 3000.

Split shares buffers 3010 may be one or more memory modules that may beused to store the multiple shares of data that resulted from the parsingand splitting of original data. In a splitting operation, split sharesbuffers 3010 hold the output of the secure data parser. In a restoreoperation, split shares buffers hold the input to secure data parser3000.

It will be understood that any other suitable arrangement ofcapabilities may be built-in for secure data parser 3000. Any additionalfeatures may be built-in and any of the features illustrated may beremoved, made more robust, made less robust, or may otherwise bemodified in any suitable way. Buffers 3008 and 3010 are likewise merelyillustrative and may be modified, removed, or added to in any suitableway.

Any suitable modules implemented in software, hardware or both may becalled by or may call to secure data parser 3000. If desired, evencapabilities that are built into secure data parser 3000 may be replacedby one or more external modules. As illustrated, some external modulesinclude random number generator 3012, cipher feedback key generator3014, hash algorithm 3016, any one or more types of encryption 3018, andkey management 3020. It will be understood that these are merelyillustrative external modules. Any other suitable modules may be used inaddition to or in place of those illustrated.

Cipher feedback key generator 3014 may, externally to secure data parser3000, generate for each secure data parser operation, a unique key, orrandom number (using, for example, random number generator 3012), to beused as a seed value for an operation that extends an original sessionkey size (e.g., a value of 128, 256, 512, or 1024 bits) into a valueequal to the length of the data to be parsed and split. Any suitablealgorithm may be used for the cipher feedback key generation, including,for example, the AES cipher feedback key generation algorithm.

In order to facilitate integration of secure data parser 3000 and itsexternal modules (i.e., secure data parser layer 3026) into anapplication layer 3024 (e.g., email application, database application,etc.), a wrapping layer that may make use of, for example, API functioncalls may be used. Any other suitable arrangement for facilitatingintegration of secure data parser layer 3026 into application layer 3024may be used.

FIG. 31 illustratively shows how the arrangement of FIG. 30 may be usedwhen a write (e.g., to a storage device), insert (e.g., in a databasefield), or transmit (e.g., across a network) command is issued inapplication layer 3024. At step 3100 data to be secured is identifiedand a call is made to the secure data parser. The call is passed throughwrapper layer 3022 where at step 3102, wrapper layer 3022 streams theinput data identified at step 3100 into assembled data buffer 3008. Alsoat step 3102, any suitable share information, filenames, any othersuitable information, or any combination thereof may be stored (e.g., asinformation 3106 at wrapper layer 3022). Secure data processor 3000 thenparses and splits the data it takes as input from assembled data buffer3008 in accordance with the present invention. It outputs the datashares into split shares buffers 3010. At step 3104, wrapper layer 3022obtains from stored information 3106 any suitable share information(i.e., stored by wrapper 3022 at step 3102) and share location(s) (e.g.,from one or more configuration files). Wrapper layer 3022 then writesthe output shares (obtained from split shares buffers 3010)appropriately (e.g., written to one or more storage devices,communicated onto a network, etc.).

FIG. 32 illustratively shows how the arrangement of FIG. 30 may be usedwhen a read (e.g., from a storage device), select (e.g., from a databasefield), or receive (e.g., from a network) occurs. At step 3200, data tobe restored is identified and a call to secure data parser 3000 is madefrom application layer 3024. At step 3202, from wrapper layer 3022, anysuitable share information is obtained and share location is determined.Wrapper layer 3022 loads the portions of data identified at step 3200into split shares buffers 3010. Secure data parser 3000 then processesthese shares in accordance with the present invention (e.g., if onlythree of four shares are available, then the redundancy capabilities ofsecure data parser 3000 may be used to restore the original data usingonly the three shares). The restored data is then stored in assembleddata buffer 3008. At step 3204, application layer 3022 converts the datastored in assembled data buffer 3008 into its original data format (ifnecessary) and provides the original data in its original format toapplication layer 3024.

It will be understood that the parsing and splitting of original dataillustrated in FIG. 31 and the restoring of portions of data intooriginal data illustrated in FIG. 32 is merely illustrative. Any othersuitable processes, components, or both may be used in addition to or inplace of those illustrated.

FIG. 33 is a block diagram of an illustrative process flow for parsingand splitting original data into two or more portions of data inaccordance with one embodiment of the present invention. As illustrated,the original data desired to be parsed and split is plain text 3306(i.e., the word “SUMMIT” is used as an example). It will be understoodthat any other type of data may be parsed and split in accordance withthe present invention. A session key 3300 is generated. If the length ofsession key 3300 is not compatible with the length of original data3306, then cipher feedback session key 3304 may be generated.

In one suitable approach, original data 3306 may be encrypted prior toparsing, splitting, or both. For example, as FIG. 33 illustrates,original data 3306 may be XORed with any suitable value (e.g., withcipher feedback session key 3304, or with any other suitable value). Itwill be understood that any other suitable encryption technique may beused in place of or in addition to the XOR technique illustrate. It willfurther be understood that although FIG. 33 is illustrated in terms ofbyte by byte operations, the operation may take place at the bit levelor at any other suitable level. It will further be understood that, ifdesired, there need not be any encryption whatsoever of original data3306.

The resultant encrypted data (or original data if no encryption tookplace) is then hashed to determine how to split the encrypted (ororiginal) data among the output buckets (e.g., of which there are fourin the illustrated example). In the illustrated example, the hashingtakes place by bytes and is a function of cipher feedback session key3304. It will be understood that this is merely illustrative. Thehashing may be performed at the bit level, if desired. The hashing maybe a function of any other suitable value besides cipher feedbacksession key 3304. In another suitable approach, hashing need not beused. Rather, any other suitable technique for splitting data may beemployed.

FIG. 34 is a block diagram of an illustrative process flow for restoringoriginal data 3306 from two or more parsed and split portions oforiginal data 3306 in accordance with one embodiment of the presentinvention. The process involves hashing the portions in reverse (i.e.,to the process of FIG. 33) as a function of cipher feedback session key3304 to restore the encrypted original data (or original data if therewas no encryption prior to the parsing and splitting). The encryptionkey may then be used to restore the original data (i.e., in theillustrated example, cipher feedback session key 3304 is used to decryptthe XOR encryption by XORing it with the encrypted data). This therestores original data 3306.

FIG. 35 shows how bit-splitting may be implemented in the example ofFIGS. 33 and 34. A hash may be used (e.g., as a function of the cipherfeedback session key, as a function of any other suitable value) todetermine a bit value at which to split each byte of data. It will beunderstood that this is merely one illustrative way in which toimplement splitting at the bit level. Any other suitable technique maybe used.

It will be understood that any reference to hash functionality madeherein may be made with respect to any suitable hash algorithm. Theseinclude for example, MD5 and SHA-1. Different hash algorithms may beused at different times and by different components of the presentinvention.

After a split point has been determined in accordance with the aboveillustrative procedure or through any other procedure or algorithm, adetermination may be made with regard to which data portions to appendeach of the left and right segments. Any suitable algorithm may be usedfor making this determination. For example, in one suitable approach, atable of all possible distributions (e.g., in the form of pairings ofdestinations for the left segment and for the right segment) may becreated, whereby a destination share value for each of the left andright segment may be determined by using any suitable hash function oncorresponding data in the session key, cipher feedback session key, orany other suitable random or pseudo-random value, which may be generatedand extended to the size of the original data. For example, a hashfunction of a corresponding byte in the random or pseudo-random valuemay be made. The output of the hash function is used to determine whichpairing of destinations (i.e., one for the left segment and one for theright segment) to select from the table of all the destinationcombinations. Based on this result, each segment of the split data unitis appended to the respective two shares indicated by the table valueselected as a result of the hash function.

Redundancy information may be appended to the data portions inaccordance with the present invention to allow for the restoration ofthe original data using fewer than all the data portions. For example,if two out of four portions are desired to be sufficient for restorationof data, then additional data from the shares may be accordinglyappended to each share in, for example, a round-robin manner (e.g.,where the size of the original data is 4 MB, then share 1 gets its ownshares as well as those of shares 2 and 3; share 2 gets its own share aswell as those of shares 3 and 4; share 3 gets its own share as well asthose of shares 4 and 1; and share 4 gets its own shares as well asthose of shares 1 and 2). Any such suitable redundancy may be used inaccordance with the present invention.

It will be understood that any other suitable parsing and splittingapproach may be used to generate portions of data from an original dataset in accordance with the present invention. For example, parsing andsplitting may be randomly or pseudo-randomly processed on a bit by bitbasis. A random or pseudo-random value may be used (e.g., session key,cipher feedback session key, etc.) whereby for each bit in the originaldata, the result of a hash function on corresponding data in the randomor pseudo-random value may indicate to which share to append therespective bit. In one suitable approach the random or pseudo-randomvalue may be generated as, or extended to, 8 times the size of theoriginal data so that the hash function may be performed on acorresponding byte of the random or pseudo-random value with respect toeach bit of the original data. Any other suitable algorithm for parsingand splitting data on a bit by bit level may be used in accordance withthe present invention. It will further be appreciated that redundancydata may be appended to the data shares such as, for example, in themanner described immediately above in accordance with the presentinvention.

In one suitable approach, parsing and splitting need not be random orpseudo-random. Rather, any suitable deterministic algorithm for parsingand splitting data may be used. For example, breaking up the originaldata into sequential shares may be employed as a parsing and splittingalgorithm. Another example is to parse and split the original data bitby bit, appending each respective bit to the data shares sequentially ina round-robin manner. It will further be appreciated that redundancydata may be appended to the data shares such as, for example, in themanner described above in accordance with the present invention.

In one embodiment of the present invention, after the secure data parsergenerates a number of portions of original data, in order to restore theoriginal data, certain one or more of the generated portions may bemandatory. For example, if one of the portions is used as anauthentication share (e.g., saved on a physical token device), and ifthe fault tolerance feature of the secure data parser is being used(i.e., where fewer than all portions are necessary to restore theoriginal data), then even though the secure data parser may have accessto a sufficient number of portions of the original data in order torestore the original data, it may require the authentication sharestored on the physical token device before it restores the originaldata. It will be understood that any number and types of particularshares may be required based on, for example, application, type of data,user, any other suitable factors, or any combination thereof.

In one suitable approach, the secure data parser or some externalcomponent to the secure data parser may encrypt one or more portions ofthe original data. The encrypted portions may be required to be providedand decrypted in order to restore the original data. The differentencrypted portions may be encrypted with different encryption keys. Forexample, this feature may be used to implement a more secure “two manrule” whereby a first user would need to have a particular shareencrypted using a first encryption and a second user would need to havea particular share encrypted using a second encryption key. In order toaccess the original data, both users would need to have their respectiveencryption keys and provide their respective portions of the originaldata. In one suitable approach, a public key may be used to encrypt oneor more data portions that may be a mandatory share required to restorethe original data. A private key may then be used to decrypt the sharein order to be used to restore to the original data.

Any such suitable paradigm may be used that makes use of mandatoryshares where fewer than all shares are needed to restore original data.

In one suitable embodiment of the present invention, distribution ofdata into a finite number of shares of data may be processed randomly orpseudo-randomly such that from a statistical perspective, theprobability that any particular share of data receives a particular unitof data is equal to the probability that any one of the remaining shareswill receive the unit of data. As a result, each share of data will havean approximately equal amount of data bits.

According to another embodiment of the present invention, each of thefinite number of shares of data need not have an equal probability ofreceiving units of data from the parsing and splitting of the originaldata. Rather certain one or more shares may have a higher or lowerprobability than the remaining shares. As a result, certain shares maybe larger or smaller in terms of bit size relative to other shares. Forexample, in a two-share scenario, one share may have a 1% probability ofreceiving a unit of data whereas the second share has a 99% probability.It should follow, therefore that once the data units have beendistributed by the secure data parser among the two share, the firstshare should have approximately 1% of the data and the second share 99%.Any suitable probabilities may be used in accordance with the presentinvention.

It will be understood that the secure data parser may be programmed todistribute data to shares according to an exact (or near exact)percentage as well. For example, the secure data parser may beprogrammed to distribute 80% of data to a first share and the remaining20% of data to a second share.

According to another embodiment of the present invention, the securedata parser may generate data shares, one or more of which havepredefined sizes. For example, the secure data parser may split originaldata into data portions where one of the portions is exactly 256 bits.In one suitable approach, if it is not possible to generate a dataportion having the requisite size, then the secure data parser may padthe portion to make it the correct size. Any suitable size may be used.

In one suitable approach, the size of a data portion may be the size ofan encryption key, a splitting key, any other suitable key, or any othersuitable data element.

As previously discussed, the secure data parser may use keys in theparsing and splitting of data. For purposes of clarity and brevity,these keys shall be referred to herein as “splitting keys.” For example,the Session Master Key, previously introduced, is one type of splittingkey. Also, as previously discussed, splitting keys may be secured withinshares of data generated by the secure data parser. Any suitablealgorithms for securing splitting keys may be used to secure them amongthe shares of data. For example, the Shamir algorithm may be used tosecure the splitting keys whereby information that may be used toreconstruct a splitting key is generated and appended to the shares ofdata. Any other such suitable algorithm may be used in accordance withthe present invention.

Similarly, any suitable encryption keys may be secured within one ormore shares of data according to any suitable algorithm such as theShamir algorithm. For example, encryption keys used to encrypt a dataset prior to parsing and splitting, encryption keys used to encrypt adata portions after parsing and splitting, or both may be secured using,for example, the Shamir algorithm or any other suitable algorithm.

According to one embodiment of the present invention, an All or NothingTransform (AoNT), such as a Full Package Transform, may be used tofurther secure data by transforming splitting keys, encryption keys, anyother suitable data elements, or any combination thereof. For example,an encryption key used to encrypt a data set prior to parsing andsplitting in accordance with the present invention may be transformed byan AoNT algorithm. The transformed encryption key may then bedistributed among the data shares according to, for example, the Shamiralgorithm or any other suitable algorithm. In order to reconstruct theencryption key, the encrypted data set must be restored (e.g., notnecessarily using all the data shares if redundancy was used inaccordance with the present invention) in order to access the necessaryinformation regarding the transformation in accordance with AoNTs as iswell known by one skilled in the art. When the original encryption keyis retrieved, it may be used to decrypt the encrypted data set toretrieve the original data set. It will be understood that the faulttolerance features of the present invention may be used in conjunctionwith the AoNT feature. Namely, redundancy data may be included in thedata portions such that fewer than all data portions are necessary torestore the encrypted data set.

It will be understood that the AoNT may be applied to encryption keysused to encrypt the data portions following parsing and splitting eitherin place of or in addition to the encryption and AoNT of the respectiveencryption key corresponding to the data set prior to parsing andsplitting. Likewise, AoNT may be applied to splitting keys.

In one embodiment of the present invention, encryption keys, splittingkeys, or both as used in accordance with the present invention may befurther encrypted using, for example, a workgroup key in order toprovide an extra level of security to a secured data set.

In one embodiment of the present invention, an audit module may beprovided that tracks whenever the secure data parser is invoked to splitdata.

FIG. 36 illustrates possible options 3600 for using the components ofthe secure data parser in accordance with the invention. Eachcombination of options is outlined below and labeled with theappropriate step numbers from FIG. 36. The secure data parser may bemodular in nature, allowing for any known algorithm to be used withineach of the function blocks shown in FIG. 36. For example, other keysplitting (e.g., secret sharing) algorithms such as Blakely may be usedin place of Shamir, or the AES encryption could be replaced by otherknown encryption algorithms such as Triple DES. The labels shown in theexample of FIG. 36 merely depict one possible combination of algorithmsfor use in one embodiment of the invention. It should be understood thatany suitable algorithm or combination of algorithms may be used in placeof the labeled algorithms.

1) 3610, 3612, 3614, 3615, 3616, 3617, 3618, 3619

Using previously encrypted data at step 3610, the data may be eventuallysplit into a predefined number of shares. If the split algorithmrequires a key, a split encryption key may be generated at step 3612using a cryptographically secure pseudo-random number generator. Thesplit encryption key may optionally be transformed using an All orNothing Transform (AoNT) into a transform split key at step 3614 beforebeing key split to the predefined number of shares with fault toleranceat step 3615. The data may then be split into the predefined number ofshares at step 3616. A fault tolerant scheme may be used at step 3617 toallow for regeneration of the data from less than the total number ofshares. Once the shares are created, authentication/integrityinformation may be embedded into the shares at step 3618. Each share maybe optionally post-encrypted at step 3619.

2) 3111, 3612, 3614, 3615, 3616, 3617, 3618, 3619

In some embodiments, the input data may be encrypted using an encryptionkey provided by a user or an external system. The external key isprovided at step 3611. For example, the key may be provided from anexternal key store. If the split algorithm requires a key, the splitencryption key may be generated using a cryptographically securepseudo-random number generator at step 3612. The split key mayoptionally be transformed using an All or Nothing Transform (AoNT) intoa transform split encryption key at step 3614 before being key split tothe predefined number of shares with fault tolerance at step 3615. Thedata is then split to a predefined number of shares at step 3616. Afault tolerant scheme may be used at step 3617 to allow for regenerationof the data from less than the total number of shares. Once the sharesare created, authentication/integrity information may be embedded intothe shares at step 3618. Each share may be optionally post-encrypted atstep 3619.

3) 3612, 3613, 3614, 3615, 3612, 3614, 3615, 3616, 3617, 3618, 3619

In some embodiments, an encryption key may be generated using acryptographically secure pseudo-random number generator at step 3612 totransform the data. Encryption of the data using the generatedencryption key may occur at step 3613. The encryption key may optionallybe transformed using an All or Nothing Transform (AoNT) into a transformencryption key at step 3614. The transform encryption key and/orgenerated encryption key may then be split into the predefined number ofshares with fault tolerance at step 3615. If the split algorithmrequires a key, generation of the split encryption key using acryptographically secure pseudo-random number generator may occur atstep 3612. The split key may optionally be transformed using an All orNothing Transform (AoNT) into a transform split encryption key at step3614 before being key split to the predefined number of shares withfault tolerance at step 3615. The data may then be split into apredefined number of shares at step 3616. A fault tolerant scheme may beused at step 3617 to allow for regeneration of the data from less thanthe total number of shares. Once the shares are created,authentication/integrity information will be embedded into the shares atstep 3618. Each share may then be optionally post-encrypted at step3619.

4) 3612, 3614, 3615, 3616, 3617, 3618, 3619

In some embodiments, the data may be split into a predefined number ofshares. If the split algorithm requires a key, generation of the splitencryption key using a cryptographically secure pseudo-random numbergenerator may occur at step 3612. The split key may optionally betransformed using an All or Nothing Transform (AoNT) into a transformedsplit key at step 3614 before being key split into the predefined numberof shares with fault tolerance at step 3615. The data may then be splitat step 3616. A fault tolerant scheme may be used at step 3617 to allowfor regeneration of the data from less than the total number of shares.Once the shares are created, authentication/integrity information may beembedded into the shares at step 3618. Each share may be optionallypost-encrypted at step 3619.

Although the above four combinations of options are preferably used insome embodiments of the invention, any other suitable combinations offeatures, steps, or options may be used with the secure data parser inother embodiments.

The secure data parser may offer flexible data protection byfacilitating physical separation. Data may be first encrypted, thensplit into shares with “m of n” fault tolerance. This allows forregeneration of the original information when less than the total numberof shares is available. For example, some shares may be lost orcorrupted in transmission. The lost or corrupted shares may be recreatedfrom fault tolerance or integrity information appended to the shares, asdiscussed in more detail below.

In order to create the shares, a number of keys are optionally utilizedby the secure data parser. These keys may include one or more of thefollowing:

Pre-encryption key: When pre-encryption of the shares is selected, anexternal key may be passed to the secure data parser. This key may begenerated and stored externally in a key store (or other location) andmay be used to optionally encrypt data prior to data splitting.

Split encryption key: This key may be generated internally and used bythe secure data parser to encrypt the data prior to splitting. This keymay then be stored securely within the shares using a key splitalgorithm.

Split session key: This key is not used with an encryption algorithm;rather, it may be used to key the data partitioning algorithms whenrandom splitting is selected. When a random split is used, a splitsession key may be generated internally and used by the secure dataparser to partition the data into shares. This key may be storedsecurely within the shares using a key splitting algorithm.

Post encryption key: When post encryption of the shares is selected, anexternal key may be passed to the secure data parser and used to postencrypt the individual shares. This key may be generated and storedexternally in a key store or other suitable location.

In some embodiments, when data is secured using the secure data parserin this way, the information may only be reassembled provided that allof the required shares and external encryption keys are present.

FIG. 37 shows illustrative overview process 3700 for using the securedata parser of the present invention in some embodiments. As describedabove, two well-suited functions for secure data parser 3706 may includeencryption 3702 and backup 3704. As such, secure data parser 3706 may beintegrated with a RAID or backup system or a hardware or softwareencryption engine in some embodiments.

The primary key processes associated with secure data parser 3706 mayinclude one or more of pre-encryption process 3708, encrypt/transformprocess 3710, key secure process 3712, parse/distribute process 3714,fault tolerance process 3716, share authentication process 3716, andpost-encryption process 3720. These processes may be executed in severalsuitable orders or combinations, as detailed in FIG. 36. The combinationand order of processes used may depend on the particular application oruse, the level of security desired, whether optional pre-encryption,post-encryption, or both, are desired, the redundancy desired, thecapabilities or performance of an underlying or integrated system, orany other suitable factor or combination of factors.

The output of illustrative process 3700 may be two or more shares 3722.As described above, data may be distributed to each of these sharesrandomly (or pseudo-randomly) in some embodiments. In other embodiments,a deterministic algorithm (or some suitable combination of random,pseudo-random, and deterministic algorithms) may be used.

In addition to the individual protection of information assets, there issometimes a requirement to share information among different groups ofusers or communities of interest. It may then be necessary to eithercontrol access to the individual shares within that group of users or toshare credentials among those users that would only allow members of thegroup to reassemble the shares. To this end, a workgroup key may bedeployed to group members in some embodiments of the invention. Theworkgroup key should be protected and kept confidential, as compromiseof the workgroup key may potentially allow those outside the group toaccess information. Some systems and methods for workgroup keydeployment and protection are discussed below.

The workgroup key concept allows for enhanced protection of informationassets by encrypting key information stored within the shares. Once thisoperation is performed, even if all required shares and external keysare discovered, an attacker has no hope of recreating the informationwithout access to the workgroup key.

FIG. 38 shows illustrative block diagram 3800 for storing key and datacomponents within the shares. In the example of diagram 3800, theoptional pre-encrypt and post-encrypt steps are omitted, although thesesteps may be included in other embodiments.

The simplified process to split the data includes encrypting the datausing encryption key 3804 at encryption stage 3802. Portions ofencryption key 3804 may then be split and stored within shares 3810 inaccordance with the present invention. Portions of split encryption key3806 may also be stored within shares 3810. Using the split encryptionkey, data 3808 is then split and stored in shares 3810.

In order to restore the data, split encryption key 3806 may be retrievedand restored in accordance with the present invention. The splitoperation may then be reversed to restore the ciphertext. Encryption key3804 may also be retrieved and restored, and the ciphertext may then bedecrypted using the encryption key.

When a workgroup key is utilized, the above process may be changedslightly to protect the encryption key with the workgroup key. Theencryption key may then be encrypted with the workgroup key prior tobeing stored within the shares. The modified steps are shown inillustrative block diagram 3900 of FIG. 39.

The simplified process to split the data using a workgroup key includesfirst encrypting the data using the encryption key at stage 3902. Theencryption key may then be encrypted with the workgroup key at stage3904. The encryption key encrypted with the workgroup key may then besplit into portions and stored with shares 3912. Split key 3908 may alsobe split and stored in shares 3912. Finally, portions of data 3910 aresplit and stored in shares 3912 using split key 3908.

In order to restore the data, the split key may be retrieved andrestored in accordance with the present invention. The split operationmay then be reversed to restore the ciphertext in accordance with thepresent invention. The encryption key (which was encrypted with theworkgroup key) may be retrieved and restored. The encryption key maythen be decrypted using the workgroup key. Finally, the ciphertext maybe decrypted using the encryption key.

There are several secure methods for deploying and protecting workgroupkeys. The selection of which method to use for a particular applicationdepends on a number of factors. These factors may include security levelrequired, cost, convenience, and the number of users in the workgroup.Some commonly used techniques used in some embodiments are providedbelow:

Hardware-Based Key Storage

Hardware-based solutions generally provide the strongest guarantees forthe security of encryption/decryption keys in an encryption system.Examples of hardware-based storage solutions include tamper-resistantkey token devices which store keys in a portable device (e.g.,smartcard/dongle), or non-portable key storage peripherals. Thesedevices are designed to prevent easy duplication of key material byunauthorized parties. Keys may be generated by a trusted authority anddistributed to users, or generated within the hardware. Additionally,many key storage systems provide for multi-factor authentication, whereuse of the keys requires access both a physical object (token) and apassphrase or biometric.

Software-Based Key Storage

While dedicated hardware-based storage may be desirable forhigh-security deployments or applications, other deployments may electto store keys directly on local hardware (e.g., disks, RAM ornon-volatile RAM stores such as USB drives). This provides a lower levelof protection against insider attacks, or in instances where an attackeris able to directly access the encryption machine.

To secure keys on disk, software-based key management often protectskeys by storing them in encrypted form under a key derived from acombination of other authentication metrics, including: passwords andpassphrases, presence of other keys (e.g., from a hardware-basedsolution), biometrics, or any suitable combination of the foregoing. Thelevel of security provided by such techniques may range from therelatively weak key protection mechanisms provided by some operatingsystems (e.g., MS Windows and Linux), to more robust solutionsimplemented using multi-factor authentication.

The secure data parser of the present invention may be advantageouslyused in a number of applications and technologies. For example, emailsystem, RAID systems, video broadcasting systems, database systems, tapebackup systems, or any other suitable system may have the secure dataparser integrated at any suitable level. As previously discussed, itwill be understand that the secure data parser may also be integratedfor protection and fault tolerance of any type of data in motion throughany transport medium, including, for example, wired, wireless, orphysical transport mediums. As one example, voice over Internet protocol(VoIP) applications may make use of the secure data parser of thepresent invention to solve problems relating to echoes and delays thatare commonly found in VoIP. The need for network retry on droppedpackets may be eliminated by using fault tolerance, which guaranteespacket delivery even with the loss of a predetermined number of shares.Packets of data (e.g., network packets) may also be efficiently splitand restored “on-the-fly” with minimal delay and buffering, resulting ina comprehensive solution for various types of data in motion. The securedata parser may act on network data packets, network voice packets, filesystem data blocks, or any other suitable unit of information. Inaddition to being integrated with a VoIP application, the secure dataparser may be integrated with a file-sharing application (e.g., apeer-to-peer file-sharing application), a video broadcastingapplication, an electronic voting or polling application (which mayimplement an electronic voting protocol and blind signatures, such asthe Sensus protocol), an email application, or any other networkapplication that may require or desire secure communication.

In some embodiments, support for network data in motion may be providedby the secure data parser of the present invention in two distinctphases—a header generation phase and a data partitioning phase.Simplified header generation process 4000 and simplified datapartitioning process 4010 are shown in FIGS. 40A and 40B, respectively.One or both of these processes may be performed on network packets, filesystem blocks, or any other suitable information.

In some embodiments, header generation process 4000 may be performed onetime at the initiation of a network packet stream. At step 4002, arandom (or pseudo-random) split encryption key, K, may be generated. Thesplit encryption key, K, may then be optionally encrypted (e.g., usingthe workgroup key described above) at AES key wrap step 4004. Althoughan AES key wrap may be used in some embodiments, any suitable keyencryption or key wrap algorithm may be used in other embodiments. AESkey wrap step 4004 may operate on the entire split encryption key, K, orthe split encryption key may be parsed into several blocks (e.g., 64-bitblocks). AES key wrap step 4004 may then operate on blocks of the splitencryption key, if desired.

At step 4006, a secret sharing algorithm (e.g., Shamir) may be used tosplit the split encryption key, K, into key shares. Each key share maythen be embedded into one of the output shares (e.g., in the shareheaders). Finally, a share integrity block and (optionally) apost-authentication tag (e.g., MAC) may be appended to the header blockof each share. Each header block may be designed to fit within a singledata packet.

After header generation is complete (e.g., using simplified headergeneration process 4000), the secure data parser may enter the datapartitioning phase using simplified data splitting process 4010. Eachincoming data packet or data block in the stream is encrypted using thesplit encryption key, K, at step 4012. At step 4014, share integrityinformation (e.g., a hash H) may be computed on the resulting ciphertextfrom step 4012. For example, a SHA-256 hash may be computed. At step4106, the data packet or data block may then be partitioned into two ormore data shares using one of the data splitting algorithms describedabove in accordance with the present invention. In some embodiments, thedata packet or data block may be split so that each data share containsa substantially random distribution of the encrypted data packet or datablock. The integrity information (e.g., hash H) may then be appended toeach data share. An optional post-authentication tag (e.g., MAC) mayalso be computed and appended to each data share in some embodiments.

Each data share may include metadata, which may be necessary to permitcorrect reconstruction of the data blocks or data packets. Thisinformation may be included in the share header. The metadata mayinclude such information as cryptographic key shares, key identities,share nonces, signatures/MAC values, and integrity blocks. In order tomaximize bandwidth efficiency, the metadata may be stored in a compactbinary format.

For example, in some embodiments, the share header includes a cleartextheader chunk, which is not encrypted and may include such elements asthe Shamir key share, per-session nonce, per-share nonce, keyidentifiers (e.g., a workgroup key identifier and a post-authenticationkey identifier). The share header may also include an encrypted headerchunk, which is encrypted with the split encryption key. An integrityheader chunk, which may include integrity checks for any number of theprevious blocks (e.g., the previous two blocks) may also be included inthe header. Any other suitable values or information may also beincluded in the share header.

As shown in illustrative share format 4100 of FIG. 41, header block 4102may be associated with two or more output blocks 4104. Each headerblock, such as header block 4102, may be designed to fit within a singlenetwork data packet. In some embodiments, after header block 4102 istransmitted from a first location to a second location, the outputblocks may then be transmitted. Alternatively, header block 4102 andoutput blocks 4104 may be transmitted at the same time in parallel. Thetransmission may occur over one or more similar or dissimilarcommunications paths.

Each output block may include data portion 4106 andintegrity/authenticity portion 4108. As described above, each data sharemay be secured using a share integrity portion including share integrityinformation (e.g., a SHA-256 hash) of the encrypted, pre-partitioneddata. To verify the integrity of the outputs blocks at recovery time,the secure data parser may compare the share integrity blocks of eachshare and then invert the split algorithm. The hash of the recovereddata may then be verified against the share hash.

As previously mentioned, in some embodiments of the present invention,the secure date parser may be used in conjunction with a tape backupsystem. For example, an individual tape may be used as a node (i.e.,portion/share) in accordance with the present invention. Any othersuitable arrangement may be used. For example, a tape library orsubsystem, which is made up of two or more tapes, may be treated as asingle node.

Redundancy may also be used with the tapes in accordance with thepresent invention. For example, if a data set is apportioned among fourtapes (i.e., portions/shares), then two of the four tapes may benecessary in order to restore the original data. It will be understoodthat any suitable number of nodes (i.e., less than the total number ofnodes) may be required to restore the original data in accordance withthe redundancy features of the present invention. This substantiallyincreases the probability for restoration when one or more tapes expire.

Each tape may also be digitally protected with a SHA-256, HMAC hashvalue, any other suitable value, or any combination thereof to insureagainst tampering. Should any data on the tape or the hash value change,that tape would not be a candidate for restoration and any minimumrequired number of tapes of the remaining tapes would be used to restorethe data.

In conventional tape backup systems, when a user calls for data to bewritten to or read from a tape, the tape management system (TMS)presents a number that corresponds to a physical tape mount. This tapemount points to a physical drive where the data will be mounted. Thetape is loaded either by a human tape operator or by a tape robot in atape silo.

Under the present invention, the physical tape mount may be considered alogical mount point that points to a number of physical tapes. This notonly increases the data capacity but also improves the performancebecause of the parallelism.

For increased performance the tape nodes may be or may include a RAIDarray of disks used for storing tape images. This allows for high-speedrestoration because the data may always be available in the protectedRAID.

In any of the foregoing embodiments, the data to be secured may bedistributed into a plurality of shares using deterministic,probabilistic, or both deterministic and probabilistic data distributiontechniques. In order to prevent an attacker from beginning a cryptoattack on any cipher block, the bits from cipher blocks may bedeterministically distributed to the shares. For example, thedistribution may be performed using the BitSegment routine, or theBlockSegment routine may be modified to allow for distribution ofportions of blocks to multiple shares. This strategy may defend againstan attacker who has accumulated less than “M” shares.

In some embodiments, a keyed secret sharing routine may be employedusing keyed information dispersal (e.g., through the use of a keyedinformation dispersal algorithm or “IDA”). The key for the keyed IDA mayalso be protected by one or more external workgroup keys, one or moreshared keys, or any combination of workgroup keys and shared keys. Inthis way, a multi-factor secret sharing scheme may be employed. Toreconstruct the data, at least “M” shares plus the workgroup key(s)(and/or shared key(s)) may be required in some embodiments. The IDA (orthe key for the IDA) may also be driven into the encryption process. Forexample, the transform may be driven into the clear text (e.g., duringthe pre-processing layer before encrypting) and may further protect theclear text before it is encrypted.

For example, in some embodiments, keyed information dispersal is used todistribute unique portions of data from a data set into two or moreshares. The keyed information dispersal may use a session key to firstencrypt the data set, to distribute unique portions of encrypted datafrom the data set into two or more encrypted data set shares, or bothencrypt the data set and distribute unique portions of encrypted datafrom the data set into the two or more encrypted data set shares. Forexample, to distribute unique portions of the data set or encrypted dataset, secret sharing (or the methods described above, such as BitSegmentor BlockSegment) may be used. The session key may then optionally betransformed (for example, using a full package transform or AoNT) andshared using, for example, secret sharing (or the keyed informationdispersal and session key).

In some embodiments, the session key may be encrypted using a shared key(e.g., a workgroup key) before unique portions of the key aredistributed or shared into two or more session key shares. Two or moreuser shares may then be formed by combining at least one encrypted dataset share and at least one session key share. In forming a user share,in some embodiments, the at least one session key share may beinterleaved into an encrypted data set share. In other embodiments, theat least one session key share may be inserted into an encrypted dataset share at a location based at least in part on the shared workgroupkey. For example, keyed information dispersal may be used to distributeeach session key share into a unique encrypted data set share to form auser share. Interleaving or inserting a session key share into anencrypted data set share at a location based at least in part on theshared workgroup may provide increased security in the face ofcryptographic attacks. In other embodiments, one or more session keyshares may be appended to the beginning or end of an encrypted data setshare to form a user share. The collection of user shares may then bestored separately on at least one data depository. The data depositoryor depositories may be located in the same physical location (forexample, on the same magnetic or tape storage device) or geographicallyseparated (for example, on physically separated servers in differentgeographic locations). To reconstruct the original data set, anauthorized set of user shares and the shared workgroup key may berequired.

Keyed information dispersal may be secure even in the face ofkey-retrieval oracles. For example, take a blockcipher E and akey-retrieval oracle for E that takes a list (X₁, Y₁), . . . , (X_(c),Y_(c)) of input/output pairs to the blockcipher, and returns a key Kthat is consistent with the input/output examples (e.g.,Y_(i)=E_(K)(X_(i)) for all i). The oracle may return the distinguishedvalue ⊥ if there is no consistent key. This oracle may model acryptanalytic attack that may recover a key from a list of input/outputexamples.

Standard blockcipher-based schemes may fail in the presence of akey-retrieval oracle. For example, CBC encryption or the CBC MAC maybecome completely insecure in the presence of a key-retrieval oracle.

If Π^(IDA) is an IDA scheme and Π^(Enc) is an encryption scheme given bya mode of operation of some blockcipher E, then (Π^(IDA), Π^(Enc))provides security in the face of a key-retrieval attack if the twoschemes, when combined with an arbitrary perfect secret-sharing scheme(PSS) as per HK1 or HK2, achieve the robust computational secret sharing(RCSS) goal, but in the model in which the adversary has a key-retrievaloracle.

If there exists an IDA scheme Π^(IDA) and an encryption scheme Π^(Enc)such that the pair of schemes provides security in the face ofkey-retrieval attacks, then one way to achieve this pair may be to havea “clever” IDA and a “dumb” encryption scheme. Another way to achievethis pair of schemes may be to have a “dumb” IDA and a “clever”encryption scheme.

To illustrate the use of a clever IDA and a dumb encryption scheme, insome embodiments, the encryption scheme may be CBC and the IDA may havea “weak privacy” property. The weak privacy property means, for example,that if the input to the IDA is a random sequence of blocks M=M₁ . . .M_(l) and the adversary obtains shares from a non-authorized collection,then there is some block index i such that it is infeasible for theadversary to compute M_(i). Such a weakly-private IDA may be built byfirst applying to Man information-theoretic AoNT, such as Stinson'sAoNT, and then applying a simple IDA such as BlockSegment, or abit-efficient IDA like Rabin's scheme (e.g., Reed-Solomon encoding).

To illustrate the use of a dumb IDA and a clever encryption scheme, insome embodiments, one may use a CBC mode with double encryption insteadof single encryption. Now any IDA may be used, even replication. Havingthe key-retrieval oracle for the blockcipher would be useless to anadversary, as the adversary will be denied any singly-encipheredinput/output example.

While a clever IDA has value, it may also be inessential in somecontexts, in the sense that the “smarts” needed to provide security inthe face of a key-retrieval attack could have been “pushed” elsewhere.For example, in some embodiments, no matter how smart the IDA, and forwhatever goal is trying to be achieved with the IDA in the context ofHK1/HK2, the smarts may be pushed out of the IDA and into the encryptionscheme, being left with a fixed and dumb IDA.

Based on the above, in some embodiments, a “universally sound” cleverIDA Π^(IDA) may be used. For example, an IDA is provided such that, forall encryption schemes Π^(Enc), the pair (Π^(IDA), Π^(Enc)) universallyprovides security in the face of key-retrieval attacks.

In some embodiments, an encryption scheme is provided that is RCSSsecure in the face of a key-retrieval oracle. The scheme may beintegrated with HK1/HK2, with any IDA, to achieve security in the faceof key-retrieval. Using the new scheme may be particularly useful, forexample, for making symmetric encryption schemes more secure againstkey-retrieval attacks.

As mentioned above, classical secret-sharing notions are typicallyunkeyed. Thus, a secret is broken into shares, or reconstructed fromthem, in a way that requires neither the dealer nor the partyreconstructing the secret to hold any kind of symmetric or asymmetrickey. The secure data parser described herein, however, is optionallykeyed. The dealer may provide a symmetric key that, if used for datasharing, may be required for data recovery. The secure data parser mayuse the symmetric key to disperse or distribute unique portions of themessage to be secured into two or more shares.

The shared key may enable multi-factor or two-factor secret-sharing(2FSS). The adversary may then be required to navigate through twofundamentally different types of security in order to break the securitymechanism. For example, to violate the secret-sharing goals, theadversary (1) may need to obtain the shares of an authorized set ofplayers, and (2) may need to obtain a secret key that it should not beable to obtain (or break the cryptographic mechanism that is keyed bythat key).

In some embodiments, a new set of additional requirements is added tothe RCSS goal. The additional requirements may include the “secondfactor”—key possession. These additional requirements may be addedwithout diminishing the original set of requirements. One set ofrequirements may relate to the adversary's inability to break the schemeif it knows the secret key but does not obtain enough shares (e.g., theclassical or first-factor requirements) while the other set ofrequirements may relate to the adversary's inability to break the schemeif it does have the secret key but manages to get hold of all of theshares (e.g., the new or second-factor requirements).

In some embodiments, there may be two second-factor requirements: aprivacy requirement and an authenticity requirement. In the privacyrequirement, a game may be involved where a secret key K and a bit b areselected by the environment. The adversary now supplies a pair ofequal-length messages in the domain of the secret-sharing scheme, M₁ ⁰and M₁ ¹. The environment computes the shares of M₁ ^(b) to get a vectorof shares, S₁=(S₁ [1], . . . , S₁ [n]), and it gives the shares S₁ (allof them) to the adversary. The adversary may now choose another pair ofmessages (M₂ ⁰, M₂ ¹) and everything proceeds as before, using the samekey K and hidden bit b. The adversary's job is to output the bit b′ thatit believes to be b. The adversary privacy advantage is one less thantwice the probability that b=b′. This games captures the notion that,even learning all the shares, the adversary still cannot learn anythingabout the shared secret if it lacks the secret key.

In the authenticity requirement, a game may be involved where theenvironment chooses a secret key K and uses this in the subsequent callsto Share and Recover. Share and Recover may have their syntax modified,in some embodiments, to reflect the presence of this key. Then theadversary makes Share requests for whatever messages M₁, . . . , M_(q)it chooses in the domain of the secret-sharing scheme. In response toeach Share request it gets the corresponding n-vector of shares, S₁, . .. , S_(q). The adversary's aim is to forge a new plaintext; it wins ifit outputs a vector of shares S′ such that, when fed to the Recoveralgorithm, results in something not in {M₁, . . . , M_(q)}. This is an“integrity of plaintext” notion.

There are two approaches to achieve multi-factor secret-sharing. Thefirst is a generic approach—generic in the sense of using an underlying(R)CSS scheme in a black-box way. An authenticated-encryption scheme isused to encrypt the message that is to be CSS-shared, and then theresulting ciphertext may be shared out, for example, using a secretsharing algorithm, such as Blakely or Shamir.

A potentially more efficient approach is to allow the shared key to bethe workgroup key. Namely, (1) the randomly generated session key of the(R)CSS scheme may be encrypted using the shared key, and (2) theencryption scheme applied to the message (e.g., the file) may bereplaced by an authenticated-encryption scheme. This approach may entailonly a minimal degradation in performance.

Although some applications of the secure data parser are describedabove, it should be clearly understood that the present invention may beintegrated with any network application in order to increase security,fault-tolerance, anonymity, or any suitable combination of theforegoing.

The parsing and/or splitting processes described above may, in someimplementations, be employed in secure file sharing applications. Insome implementations, the secure filing sharing is performed by theillustrative secure sharing system 4200 depicted in the block diagramsof FIG. 42.

FIG. 42A depicts two user computing devices, User 1 device 4202 a andUser 2 device 4202 b. One or more data sets may be stored in memory onUser 1 device 4202 a, such as file ANYFILE1 4204 a and files stored inthe directory SHARED\ 4206 a. Similarly, one or more data sets may bestored in memory on User 2 device. User 1 device 4202 a and User 2device 4202 b are each in communication (via one or more wireless orwired communications networks, not shown) with multiple storagedepositories 4208 a, 4208 b and 4208 c. The storage depositories 4208 a,4208 b and 4208 c are illustrated as being located in computing cloudstorage, but may be any suitable network-attached storage devices, suchas those provided by at least one network storage provider. It will beunderstood in FIG. 42 that any suitable number and any suitable types ofnetwork storage providers may be used. In some implementations, such asthe implementation illustrated in FIG. 42, a secure sharing systemincludes at least three storage depositories (e.g., three cloud storageproviders). In some implementations, the number of storage depositoriesincluded in a secure sharing system is equal to the number of sharesinto which data is split (e.g., four storage depositories in a 3 of 4cryptographic split), as described in detail herein. The storagedepositories may be managed by storage provider servers, each of whichmay be configured to supply storage on-demand, authenticate access tothe storage, and provide upload, download, delete, and listfunctionality.

User 1 device 4202 a and User 2 device 4202 b are also each incommunication (via one or more wireless or wired communicationsnetworks, not shown) with registration server 4210. Registration server4210 may be configured to register users of secure sharing system 4200(including individual users, user devices, and groups of users ordevices), store user credentials such as e-mail address or username,authenticate users (e.g., based on the stored credentials), look up auser by their e-mail address or other credentials, transmit a public keyto a cryptographic sharing client (as described in detail below),de-authorize one or more users from accessing registration server 4210,accept payment for use of one or more aspects of secure sharing system4200, and enforce the expiration of a user's access to registrationserver 4200.

User 1 device 4202 a and User 2 device 4202 b each include processorsconfigured to execute a cryptographic sharing client. In someimplementations, the cryptographic sharing client provides cryptographicsplitting operations as described above with respect to the secureparser and other systems disclosed herein. In some implementations,during initial configuration of a user device with the cryptographicsharing client (e.g., during installation of a cryptographic sharingclient software package), the cryptographic sharing client creates ashared directory in the user device (e.g., the directory SHARED\ 4206 aduring installation of the cryptographic sharing client in User 1 device4202 a, or the directory SHARED\ 4206 b during installation of thecryptographic sharing client in User 2 device 4202 b). During initialconfiguration, the cryptographic sharing client may capture informationidentifying a user associated with the user device (such as a usernameand e-mail address) and may generate an asymmetric key pair (including aprivate key and a public key) associated with that user. Thecryptographic sharing client stores the private key locally to the userdevice (e.g., in a memory device included with the user device or in amemory device locally connected or securely available to the userdevice), and transmits the public key for storage at registration server4210. In some implementations, registration server 4210 may also storeany suitable group information that may define a group of user or userdevices (e.g., by usernames or other identifying information or by userdevice identification information). Group affiliations may be providedto registration server 4210 when the user device communications withregistration server 4210. For example, a group to which a user devicebelongs may be indicated by a sender of a secure e-mail when attemptingto transmit data to other members of the group. In some implementations,the user devices that access registration server 4210 may be designatedusing access groups such as “sharing” workgroups.

The operation of secure sharing system 4200 will now be illustrated byan example in which User 1, the user associated with User 1 device 4202a, wishes to securely share the file ANYFILE1 4204 a with User 2, theuser associated with User 2 device 4202 b. User 1 is associated with aprivate-public key pair Pri-U1 4214 a and Pub-U1 4212 a, and User 2 isassociated with a private-public key pair Pri-U2 4214 b and Pub-U2 4212b. The public keys associated with Users 1 and 2, Pub-U1 4212 a andPub-U2 4212 b, are stored in registration server 4210, while the privatekeys Pri-U1 4214 a and Pri-U2 4214 b are locally available to User 1device 4202 a and User 2 device 4202 b, respectively. In someimplementations, every user or user device may be associated with arespective private-public key pair. In some implementations, a workgroupor collection of users or user devices may share a private key andcorresponding public key. The public keys for users of the securesharing system 4200 are stored on the registration server 4210 and maybe retrieved by a user's respective cryptographic sharing client.

FIG. 42A illustrates User 1 initiating a secure sharing process bymoving file ANYFILE1 4204 a into the directory SHARED\ 4206 a. Thistechnique for initiating a secure sharing process is not unique, andmany other techniques may be used. In some implementations, User 1 mayaccess the cryptographic sharing client by selecting an icon in thesystem tray of an operating system. In some implementations, User 1 mayselect ANYFILE1 4204 a on a display by right-clicking on an image of thefile with a mouse, and may then select “Cryptographic Sharing” as anoption from a pull-down menu displayed by the cryptographic sharingclient in response to the right-click. User 1 may then identify theindividual or group with which ANYFILE1 4204 a is to be shared, e.g., byselecting an individual or group e-mail address from a list of e-mailaddresses. This list may be populated in a manner common to all users ofthe secure sharing system 4200 (e.g., using an e-mail lookup of allusers), or may be populated using information about User 1's pastsharing or other communication activities. For example, the list ofe-mail addresses may be populated by identifying the users to which User1 has previously securely shared files or sent e-mails. Otheridentifying, such as usernames or real names, may be used instead of orin addition to e-mail addresses.

FIG. 42B illustrates the cryptographic sharing client of User 1 device4202 a accessing registration server 4210 to retrieve the public keyPub-U2 4212 b associated with User 2. In some implementations, User 1device 4202 a must authenticate itself to registration server 4210before access to the public key Pub-U2 4212 b is allowed. Thecryptographic sharing client of User 1 device 4202 a may do so bysupplying identifying information, such as User 1's e-mail address. User1 device 4202 a also accesses the public key Pub-U1 4212 a associatedwith User 1, which may be stored locally to User 1 device 4202 a orretrieved from registration server 4210. To begin securing the fileANYFILE1 4204 a for transfer, the cryptographic sharing client of User 1device 4202 a encrypts the file ANYFILE1 4204 a using a file sessionkey. In some implementations, the file session key is a workgroup key oran internal key. Once the public keys Pub-U1 4212 a and Pub-U2 4212 bare available, the cryptographic sharing client of User 1 device 4202 aencrypts the file session key using User 1's public key Pub-U1 4212 a toform a first encrypted key, and encrypts the file session key using User2's public key Pub-U2 4212 b to form a second encrypted key. In someimplementations, before the file session key is encrypted with User 2'spublic key Pub-U2 4212 b, the file session key is encrypted with aworkgroup key to which User 2 has access. In some implementations, thefile session key is encrypted with an additional internal key encryptionkey (KEK) generated by the cryptographic sharing client of User 1 device4202 a. It will be understood that the file session key may be encryptedin one or more rounds of encryption, using the same or differentencryption techniques and the same or different encryption keys. Thecryptographic sharing client of User 1 device 4202 a may also sign theencrypted key using the private key Pri-U1 4214 a associated with User 1in order to authenticate the encrypted key. In some implementations, thefirst and second encrypted keys are packaged with the encrypted data, aspart of the encrypted data at-rest, or are packaged with the encrypteddata in-motion as data packet headers or in a dedicated header packet ofthe encrypted data that is transmitted to storage depositories 4208 a,4208 b and 4208 c, as described below.

Next, the cryptographic sharing client of User 1 device 4202 acryptographically splits the file ANYFILE1 4204 a into two or moreshares using the private key Pri-U1 4214 a associated with User 1 andthe public key Pub-U2 4212 b associated with User 2 such that only userswith access to the private key Pri-U1 4214 a associated with User 1 oraccess to the private key Pri-U2 4214 b associated with User 2 canrestore the file ANYFILE1 4204 a. The cryptographic splitting mayinvolve any suitable cryptographic splitting process such as thecryptographic splitting process described above in which data is splitinto a certain redundant number of cryptographic shares, e.g., 2 of 3shares. More generally, the file may be split into M of N shares, whereM is at least one less than N and M shares are required to reconstituteor reassemble the file so as to provide sufficient redundancy in theshares such that only a subset of the shares are needed to reassemble orrestore the data to its original or useable form. In someimplementations, a secure parser generates the shares of data and/orencrypts the shares and uses a protocol that includes wrapping thesession key with a workgroup key, as described above. In suchimplementations, secure sharing system 4200 may create a one-timesymmetric key which is used to wrap the session key (as the workgroupkey described above typically would). The wrapped session key is thenfurther encrypted with the public keys Pub-U1 4212 a associated withUser 1 and Pub-U2 4212 b associated with User 2 to form first and secondencrypted keys, as described above. The one-time symmetric key may bediscarded after the cryptographic sharing client of User 2 device 4202 bdecrypts the session key, for example, as described below. In someimplementations, the workgroup key or one-time key may be an asymmetrickey (e.g., a public key of a private-public key pair). It will beunderstood that splitting operations and encryption operations may beperformed in any order. For example, a data set may be split intoshares, then the shares encrypted, or a data set may be encrypted thensplit into shares. Multiple splitting and multiple encryption operationsmay also be performed, in any order. Additionally, any additional keysused to encrypt the file session key (e.g., a KEK) may themselves besplit and encrypted any number of times in any suitable order. Theseshares of encrypted additional keys may be stored and transmitted in anyof the ways described below for encrypted data and encrypted keys. Thesecure sharing techniques disclosed herein may be advantageously usedwith other cryptographic or security systems already in place bysecuring the encryption keys used in these in-place systems withadditional layers of security without interfering with or compromisingthe in-place systems. In particular, data security systems that includeinternal session or workgroup keys may continue to use these keys tosecure data, with the secure sharing system of FIG. 42 operating on topof such systems to enable secure data sharing.

FIG. 42C illustrates the cryptographic sharing client of User 1 device4202 distributing the shares to storage depositories 4208 a, 4208 b and4208 c. Each of the multiple storage depositories 4208 a, 4208 b and4208 c may only receive a number of shares that is less than the numberof shares needed to restore the file ANYFILE1 4204 a. In someimplementations, only one share is sent to each one of storagedepositories 4208 a, 4208 b and 4208 c. In some implementations, theshares are temporarily stored in the storage depositories 4208 a, 4208 band 4208 c (e.g., when the file ANYFILE1 4204 a is securely attached toan e-mail that will be later transmitted to User 2 device 4202 b).Temporary storage may end, for example, after a predetermined period oftime has elapsed, or when a particular event occurs (e.g., when the fileANYFILE1 4204 a is retrieved by User 2 device 4202 b from the storagedepositories 4208 a, 42088 b and 4208 c). In such implementations, thestorage depositories 4208 a, 4208 b and 4208 c may include one or moretemporary cloud storage servers, for example. In some implementations,the shares are persistently stored in the storage depositories 4208 a,4208 b and 4208 c (e.g., when the file ANYFILE1 4204 a is part of ashared directory that may be accessed by one or more authorized users).In such implementations, the storage depositories 4208 a, 4208 b and4208 c may include one or more persistent or permanent cloud storageservers. Data stored on a persistent basis may be subject to deletionafter a suitable time period (e.g., one year). The expiration period fortemporary or persistent storage may be set by one or more of storagedepositories 4208 a, 4208 b and 4208 c, or by registration server 4210.The shares of data stored in the storage depositories 4208 a, 4208 b and4208 c may be stored as files, objects, or in any other suitable form,and the form may differ between depositories. In implementations inwhich the encrypted file session key was also signed using the privatekey Pri-U1 4214 a associated with User 1, a user attempting to accessthe stored data may also have to validate the encrypted file session keyusing the public key Pub-U1 4212 a associated with User 1 (as retrievedfrom registration server 4210). User 2 can restore the file afterauthentication that the file was transmitted by User 1.

FIG. 42D illustrates the cryptographic sharing client of User 2 device4202 b retrieving some or all of the shares from storage depositories4208 a, 4208 b and 4208 c. Although FIG. 42D shows User 2 device 4202 baccessing all three of the storage depositories, User 2 device 4202 bmay only access some of the storage depositories on which shares arestored, as long as a sufficient number of shares may be retrieved torestore the file ANYFILE1 4204 a. In some implementations, thecryptographic sharing client of User 2 device 4202 b periodically scansand downloads data from storage depositories 4208 a, 4208 b and 4208 cto storage local to User 2 device 4202 b. This periodic scanning anddownloading may be performed by a batch processing software applicationrunning on the cryptographic sharing client (e.g., as a backgroundtask), but data being shared with User 2 device 4202 b may be retrievedusing any suitable technique. For example, the registration server 4210may cause the data to be pushed to User 2 device 4202 b (e.g., byrecognizing identifying information of User 2 or User 2 device 4202 btransmitted or stored with one or more of the shares). In someimplementations, User 2 device 4202 b periodically polls registrationserver 4210 or storage depositories 4208 a, 4208 b and 4208 c todetermine if any data has been provided that is to be shared with User 2device 4202 b. In some implementations, registration server 4210provides a notification to User 2 or User 2 device 4202 b (such as ane-mail alert) that a file has been placed in the directory SHARED\ 4206a of User 1 device 4202 a, or that data intended for User 2 is availableon one or more of storage depositories 4208 a, 4208 b and 4208 c. User 2device 4202 b may, in response to this notification, pull sufficientshares for restoration of ANYFILE1 4204 a from storage depositories 4208a, 4208 b and 4208 c.

Once one or more shares has been retrieved from storage depositories4208 a, 4208 b and 4208 c, the cryptographic sharing client of User 2device 4202 b then validates the encrypted file session key using thepublic key Pub-U1 4212 a associated with User 1 (if the encrypted filesession key was signed by the cryptographic sharing client of User 1device 4202 a), then decrypts the second encrypted key to restore thefile session key using the private key Pri-U2 4214 b associated withUser 2. If a sufficient number of shares have been received forrestoration, the cryptographic sharing client of User 2 device 4202 bthen restores the shared file ANYFILE1 4204 b at User 2 device 4202 b.In this manner, the file ANYFILE1 4204 a is securely shared with User 2.The restored file ANYFILE 1 4204 b may be stored locally to User 2device 4202 b; for example, in the directory SHARED\ 4206 b as shown inFIG. 42E. Any suitable messaging or notifications may be provided toUser 1, User 2, or both, to indicate the status or progression of thesecure sharing process. For example, a notification may be provided byregistration server 4210 to User 1, User 1, or both, when a the publickey Pub-U2 4212 b associated with User 2 is accessed at registrationserver 4210 by the cryptographic sharing client of User 1 device 4202 a,indicating that sharing has begun, or when a the public key Pub-U1 4212a associated with User 1 is accessed at registration server 4210 by thecryptographic sharing client of User 2 device 4202 b, indicating thatvalidation has begun.

The foregoing discussion of FIG. 42 has focused on the retrieval ofsecurely shared data from storage depositories 42084 a, 4208 b and 4208c by User 2 device 4202 b, but the data may also be retrieved by User 1device 4202 a by decrypting the first encrypted key (e.g., the filesession key encrypted with the public key Pub-U1 4212 a) to restore thefile session key, then decrypting the encrypted data set using the filesession key. Thus, User 1 device 4202 a may have access to the securelyshared file along with any other desired users. Additionally, althoughthe cryptographic sharing client is discussed as executed at the userdevices in FIG. 42, in some implementations, the cryptographic sharingclient is executed at one or more central servers, such as a corporateserver. In some such implementations, the central server(s) may holdprivate keys for the users, perform the cryptographic splittingoperations described herein, and may store the securely shared data.

It will be understood that the securing sharing systems and techniquesdescribed above with reference to FIG. 42 can enable secure sharingbetween any combination of an individual user, multiple individualusers, a group of individual users (e.g., a workgroup), and multiplegroups of individual users. For example, a user may use secure sharingsystem 4200 to securely store files for his or her own use by treatingthe user as both User 1 and User 2 in the techniques described abovewith reference to FIG. 42. In some implementations, if User 1 wishes toshare ANYFILE1 4204 a with User 2 and a third user, User 3, thecryptographic sharing client of User 1 device 4202 a may perform theoperations described above for sharing ANYFILE1 4204 a with User 2, andmay also perform the analogous operations described above for sharingANYFILE1 4204 a with User 3.

FIG. 43 illustrates an implementation in which a cryptographic sharingclient of a user device is configured to perform a combined sharingoperation to securely share a data set with a plurality of users (User 1through User M in FIG. 43). This plurality of users may include the userdevice that is configured to perform the sharing operations. In FIG. 43,for each user, the cryptographic sharing client of the user deviceretrieves a public key associated with that user (e.g., fromregistration server 4210 of FIG. 42) and encrypts the file session key(the key used to encrypt the data set as described above with referenceto the encryption of the file ANYFILE1 4204 a in FIG. 42B) with thatpublic key. For example, as shown in FIG. 43, the cryptographic sharingclient encrypts the session key with the public key associated with User1 (operation 4306) to form encrypted key 4308, and performs an analogousencryption of the symmetric key with the public keys associated with theremaining other users, up to User M (encrypted key 4310). Next, theencrypted keys are packaged with each of N shares 4312 of encrypted dataset 4314, as part of the encrypted data at-rest, or packaged with theencrypted data in-motion as data packet headers or in a dedicated headerpacket of the encrypted data that is transmitted to storage depositories4208 a, 4208 b and 4208 c. When the cryptographic sharing client of auser device associated with User M, for example, attempts to retrieveand restore the data, the session key encrypted with User M's public key(encrypted key 4310) can be decrypted with the private key associatedwith User M, as described above with reference to User 2 device 4202 bof FIG. 42. In this manner, data may be securely shared with any numberof users of secure sharing system 4200 by making an session keyencrypted with a user's public key available to each user, along withthe data encrypted with the session key. In preferred implementations,the session key is a symmetric key, or a symmetric key encrypted with aworkgroup key.

In some implementations, the cryptographic sharing client used in securesharing system 4200 may be configured to be interoperable with otherclients, such as SPxClient (produced by Security First Corp. of RanchoSanta Margarita, Calif.), for securing local data. In suchimplementations, SPxClient may be used to secure data locally, and thelocally secured data may be securely shared using secure sharing system4200. In some implementations, additional secure communication softwaresuch as SPxConnect (also produced by Security First Corp.) may be usedto secure communications between a local machine and a web server orother server (e.g., between User 1 device 4202 a and registration server4210, or between User 1 device 4202 a and storage depositories 4208 a,4208 b and 4208 c). In some implementations, the communications may beperformed without the encryption key from the cryptographic sharingclient by using a different key management system to create the secureconnection. In some implementations, secure parsing software such asSPxBitFiler (also produced by Security First Corp.) may be used inenterprise settings, with data secured by SPxBitFiler shared usingsecure sharing system 4200.

In some implementations, use of secure sharing system 4200 may besubject to tiered pricing depending upon the level of use. For example,the pricing may be based on the size of the shared files. In some suchimplementations, each price tier is associated with a maximum file sizewhich secure sharing system 4200 will handle for a user paying the tierprice (e.g., 2 GB). In some such implementations, each price tier isassociated with a range of the total amount of data securely shared in atime period (e.g., a first price for 0-10 GB/month and a second pricefor 10-20 GB/month) or other suitable metric of volume of use (e.g., thenumber of files securely shared in a month). The tiered pricing may bebased on the types of files shared (e.g., blobs or other file types).The tiered pricing may be based on the data throughput to thedepositories in the cloud storage, with predetermined limits based onprice paid or by varying the price charged based on the actualthroughput. Secure sharing system 4200 may include a payment serverconfigured to bill users and receive credit card payments or otherelectronic payments according to the tiered pricing.

FIG. 44 is a flow diagram of illustrative steps of a method for securelysharing data. At step 4402, a processor (e.g., a processor associatedwith a first user device, such as User 1 device 4202 a of FIG. 42,configured with a cryptographic sharing client) generates an encrypteddata set by encrypting a data set from a first user device (such as User1 device 4202 a of FIG. 42) with a symmetric key. At step 4404, theprocessor generates a first encrypted key by encrypting data indicativeof the symmetric key with a first asymmetric key (e.g., a public key) ofa first asymmetric key pair associated with a first user device (such asUser 1 device 4202 a of FIG. 42). In some implementations, step 4402need not be performed by the processor and the method may begin with theencrypted data set and symmetric key at step 4404. At step 4406, theprocessor generates a second encrypted key by encrypting data indicativeof the symmetric key with a first asymmetric key (e.g., a public key) ofa second asymmetric key pair associated with a second user device (suchas User 2 device 4202 b of FIG. 42). The first asymmetric key of thefirst and/or second asymmetric key pair may be accessed from aregistration server (e.g., registration server 4210 of FIG. 42). Thedata indicative of the symmetric key may be the symmetric key itself orthe symmetric key encrypted with one or more keys for workgroups towhich the second user device has access, for example. At step 4408, theprocessor forms two or more shares of the encrypted data set, eachencrypted data set share including a portion of data from the encrypteddata set generated at step 4402. At step 4410, the processor causes thefirst and second encrypted keys to be stored in at least one storagelocation and the two or more encrypted data set shares to be storedseparately from each other in at least one storage location. The atleast one storage location (e.g., a cloud storage location) is remote toboth the first and second user devices. To restore the data set, apredetermined number of the two or more encrypted data set shares (e.g.,2 of 3) and at least one of the second asymmetric keys (e.g., a privatekey) of the first or second asymmetric key pair are needed.

In some implementations, the processor performs steps 4406 and 4410 fora plurality of user devices by generating a plurality of encrypted keys(step 4406) and causing the plurality of encrypted keys to be stored(step 4410). To do so, for each of a plurality of first asymmetric keys(e.g., the public keys) of a corresponding plurality of asymmetric keypairs associated with the plurality of user devices, the processorencrypts the data indicative of the symmetric key with the firstasymmetric key to form the plurality of encrypted keys (step 4406). Theprocessor then causes the plurality of encrypted keys to be stored inthe at least one storage location (step 4410). In some implementations,the processor transmits the plurality of encrypted keys in a header ofeach of the two or more encrypted data set shares. To restore the dataset, at least one of the plurality of second encryption keys (e.g., theprivate keys) of the plurality of asymmetric key pairs are needed, inaddition to the predetermined number of the two or more encrypted dataset shares.

FIG. 45 is a flow diagram of illustrative sub-steps that a processor mayperform in the course of performing step 4410 of FIG. 44, in which theprocessor causes the encrypted keys to be stored in at least one storagelocation. At step 4502, the processor forms two or more shares of thefirst and second encrypted key. The first and second encrypted keys maybe formed into shares separately, or combined and then formed intoshares. Each encrypted key share includes a portion of data from theencrypted key. At step 4504, the processor causes the two or moreencrypted key shares to be stored separately from each other in the atleast one storage location (discussed above with reference to FIG. 44).To restore the encrypted keys, a predetermined number of the two or moreencrypted key shares (e.g., 3 of 4) is needed.

FIG. 46 is a flow diagram of illustrative steps of a method foraccessing a data set shared securely according to the method illustratedin FIG. 44. At step 4602, a processor accesses an encrypted key and apredetermined number of encrypted data set shares stored in at least onestorage location. The encrypted key comprises data indicative of asymmetric key encrypted with a first asymmetric key (e.g., a public key)of a first asymmetric key pair associated with a first user device(e.g., User 2 device 4202 b of FIG. 42). The first asymmetric key mayhave been previously provided to a registration server (e.g.,registration server 4210 of FIG. 42). The encrypted data set shares wereencrypted with the symmetric key by a second user device different fromthe first user device (e.g., User 1 device 4202 a of FIG. 42). A firstasymmetric key of a second asymmetric key pair associated with thesecond user device is also stored at the at least one storage location.The at least one storage location is remote from the first and seconduser devices. At step 4604, the processor restores the data indicativeof the symmetric key by decrypting the encrypted key using a secondasymmetric key (e.g., a private key) of the asymmetric key pair. At step4606, the processor restores the encrypted data set from thepredetermined number of encrypted data set shares (accessed at step4602) and the data indicative of the symmetric key.

FIG. 47 is a flow diagram of illustrative steps of a method for securelysharing data. An implementation of the method of FIG. 47 is discussedabove with reference to FIG. 43. Steps of the flow diagram of FIG. 47that are similar to steps of the flow diagram of FIG. 44 may beperformed in a similar manner. At step 4702, a processor (e.g., aprocessor associated with a first user device, such as User 1 device4202 a of FIG. 42, configured with a cryptographic sharing client)generates an encrypted data set by encrypting a data set from a firstuser device with a symmetric key. At step 4704, the processor forms twoor more shares of the encrypted data set, each encrypted data set shareincluding a portion of data from the encrypted data set (generated atstep 4702). In some implementations, step 4702 need not be performed bythe processor and the method may begin with the encrypted data set andsymmetric key at step 4704. At step 4706, for each of a plurality ofuser devices, including the first user device, the processor generatesan encrypted key by encrypting data indicative of the symmetric key witha first asymmetric key of an asymmetric key pair associated with theuser device. At step 4708, for each of the two or more encrypted dataset shares, the processor distributes the plurality of encrypted keys ina header of the encrypted data set share. At step 4710, the processorcauses the two or more encrypted data set shares and headers to bestored in at least one storage location. To restore the data set, apredetermined number of the two or more encrypted data set shares and asecond asymmetric key of at least one of the plurality of asymmetric keypairs are needed.

Those skilled in the art will realize that secure sharing may berealized by secure sharing systems that are modifications or variationsof the systems described above. Thus, inasmuch as implementations havebeen described with respect to the secure sharing system of FIG. 42,these implementations are intended to be illustrative and not limitingof the present invention.

What is claimed is:
 1. A computer-implemented method for securelysharing data, the method comprising: causing, using at least onehardware processor, two or more shares of an encrypted data set to bestored separately from each other in at least one storage location, eachof the shares comprising a portion of the encrypted data set, whereinthe encrypted data set is encrypted using a cryptographic key;generating, using the at least one hardware processor, a first encryptedkey by encrypting data indicative of the cryptographic key using a firstasymmetric key of a first asymmetric key pair; generating, using the atleast one hardware processor, a second encrypted key by encrypting thedata indicative of the cryptographic key using a first asymmetric key ofa second asymmetric key pair, the second asymmetric key pair beingdifferent from the first asymmetric key pair; generating, using the atleast one hardware processor, two or more encrypted key shares from thefirst and second encrypted keys, each encrypted key share comprising aportion of the first and second encrypted keys; and causing, using theat least one hardware processor, the two or more encrypted key shares tobe stored separately in the at least one storage location; wherein thedata indicative of the cryptographic key is restorable from the two ormore encrypted key shares and at least one of a second asymmetric key ofthe first asymmetric key pair and a second asymmetric key of the secondasymmetric key pair; and wherein the data set is restorable from aminimum number of the two or more shares and at least one of a secondasymmetric key of the first asymmetric key pair and a second asymmetrickey of the second asymmetric key pair.
 2. The method of claim 1, whereinthe cryptographic key is selected from a group consisting of a splitkey, an encryption key, a session key, a workgroup key, a symmetric key,and an asymmetric key.
 3. The method of claim 1, wherein the dataindicative of the cryptographic key and the cryptographic key form anasymmetric key pair.
 4. The method of claim 1, wherein the minimumnumber is all of the shares.
 5. The method of claim 1, wherein theminimum number is fewer than all of the shares.
 6. The method of claim1, wherein the first asymmetric key pair is associated with a first userdevice, the second asymmetric key pair is associated with a second userdevice, and the data set is associated with the first user device. 7.The method of claim 1, wherein the at least one storage locationcomprises a cloud computing storage location.
 8. The method of claim 1,further comprising: accessing the first asymmetric key of the secondasymmetric key pair from a registration server prior to generating thesecond encrypted key.
 9. The method of claim 1, further comprisinggenerating the two or more shares of the encrypted data set using asubstantially random technique.
 10. The method of claim 1, furthercomprising generating the two or more shares of the encrypted data setusing a deterministic technique.
 11. The method of claim 1, wherein theportion of the encrypted data set comprises a portion of the encrypteddata set that has been shuffled from an original order.
 12. The methodof claim 1, wherein causing the first and second encrypted keys to bestored in the at least one storage location comprises transmitting thefirst and second encrypted keys in a header of each of the two or moreshares of the encrypted data set.
 13. A computer system for securelysharing data, comprising: at least one hardware processor configured to:cause two or more shares of an encrypted data set to be storedseparately from each other in at least one storage location, each of theshares comprising a portion of the encrypted data set, wherein theencrypted data set is encrypted using a cryptographic key; generate afirst encrypted key by encrypting data indicative of the cryptographickey using a first asymmetric key of a first asymmetric key pair;generate a second encrypted key by encrypting the data indicative of thecryptographic key using a first asymmetric key of a second asymmetrickey pair, the second asymmetric key pair being different from the firstasymmetric key pair; generate two or more encrypted key shares from thefirst and second encrypted keys, each encrypted key share comprising aportion from the first and second encrypted keys; and cause the two ormore encrypted key shares to be stored separately in the at least onestorage location; wherein the data indicative of the cryptographic keyis restorable from the two or more encrypted key shares and at least oneof a second asymmetric key of the first asymmetric key pair and a secondasymmetric key of the second asymmetric key pair; and wherein the dataset is restorable from a minimum number of the two or more shares and atleast one of a second asymmetric key of the first asymmetric key pairand a second asymmetric key of the second asymmetric key pair.
 14. Thesystem of claim 13, wherein the cryptographic key is selected from agroup consisting of a split key, an encryption key, a session key, aworkgroup key, a symmetric key, and an asymmetric key.
 15. The system ofclaim 13, wherein the data indicative of the cryptographic key and thecryptographic key form an asymmetric key pair.
 16. The system of claim13, wherein the minimum number is all of the shares.
 17. The system ofclaim 13, wherein the minimum number is fewer than all of the shares.18. The system of claim 13, wherein the first asymmetric key pair isassociated with a first user device, the second asymmetric key pair isassociated with a second user device, and the data set is associatedwith the first user device.
 19. The system of claim 13, wherein the atleast one storage location comprises a cloud computing storage location.20. The system of claim 13, wherein the at least one hardware processoris further configured to: access the first asymmetric key of the secondasymmetric key pair from a registration server prior to generating thesecond encrypted key.
 21. The system of claim 13, wherein the at leastone hardware processor is further configured to: generate the two ormore shares of the encrypted data set using a substantially randomtechnique.
 22. The system of claim 13, wherein the at least one hardwareprocessor is further configured to: generate the two or more shares ofthe encrypted data set using a deterministic technique.
 23. The systemof claim 13, wherein the portion of the encrypted data set comprises aportion of the encrypted data set that has been shuffled from anoriginal order.
 24. The system of claim 13, wherein the at least onehardware processor is configured to cause the first and second encryptedkeys to be stored in the at least one storage location by transmittingthe first and second encrypted keys in a header of each of the two ormore shares of the encrypted data set.